Countries welcoming US tourists back

(CNN) — US passport holders have more international travel options now than at any point during the Covid-19 pandemic.

Total US cases are nearing the 33.6 million mark since the pandemic started, but the rate of new cases has been slowing down recently. The United States is one of the world leaders in vaccination rates and has been leading among nations with a population over 100 million. But we're not out of the woods -- the US Centers for Disease Control and Prevention said June 15 that the Delta variant of the novel coronavirus, also known as B.1.617.2, is a "variant of concern."

Still, more and more of Europe is opening up to US leisure travelers in time for summer -- especially the fully vaccinated. Germany and Austria are just two of the latest to open their doors. The global situation is in flux, though. Even as some places reopen for the first time, others are closing back up.

In the end, it's up to you to decide whether travel to international destinations is a good idea. The health risks are obvious if you're not fully vaccinated. Nations might change their rules at any time. You may have to adhere to strict curfews and mask mandates. Violations could involve big fines and even jail time.

If you want expert input into your decision, the US State Department and the CDC provide Covid-19 risk assessments by country. Both agencies rate many of the countries open to US travelers at Level 4, the highest risk for Covid-19. Also, remember that all air passengers 2 and older must show proof of a negative Covid-19 test that's no more than three days old to enter the United States.

What follows is an alphabetical list of countries and territories where it's still possible for US passport holders to go for a vacation. Click the links we've provided for very important information on:

-- Presenting negative results from Covid-19 tests to enter (including time limits to take the test, types of tests allowed and additional tests upon arrival).
-- Quarantines (if any) and health screenings.
-- Possible exemptions from the rules for the fully vaccinated or people recovered from a recent case of Covid-19.
-- Health insurance requirements, curfews and lockdowns.

These are all things you need to research before you book your trip. People testing positive for Covid-19 upon arrival or while visiting can expect to go into quarantine. Rules for land entry may be different.

Albania

Blessed with a gorgeous Adriatic Sea coastline, this southeastern European country has no test requirements or quarantine. Details and updates: US Embassy.

Anguilla

This upscale British island in the Eastern Caribbean has reopened. Testing and quarantine requirements are in place. Details and updates: US Embassy | Anguilla International Travelers.

Antigua and Barbuda

This independent nation in the eastern Caribbean, known for sheltered bays and historical sites, is open. Testing and quarantine requirements are in place. Details and updates: US Embassy | Antigua and Barbuda government website.

Armenia

From the historic capital of Yerevan to wild national parks, Armenia is open to US tourists. Testing required; quarantines in some circumstances. Details and updates: US Embassy | Armenia's official Covid-19 travel website.

Aruba

Scroll down to the Dutch Caribbean entry below for information on Aruba and other islands in this group.

Austria

US citizens can now visit this Alpine nation renowned for its culture and food. You must have negative Covid-19 test or proof of vaccination or proof of past infection to enter. No quarantine in place. Details and updates: US Embassy | Austria Entry Requirements.

The Bahamas

Off the coast of Florida, this large chain of islands is loved for its many beaches. Testing required; exemptions for the fully vaccinated. No quarantine in place. Details and updates: US Embassy | Bahamas travel website | Bahamas Travel Health Visa.

Bangladesh

This populous South Asian nation offers beaches, interesting architecture and cultural experiences. Testing and quarantine requirements are in place. Details and updates: US Embassy.

Barbados

Belgium

Home to historic Bruges and busy Brussels, Belgium is now open. No testing required for citizens of the US, currently labeled as an "orange zone" nation; no quarantine unless arriving from a "red zone" nation. Details and updates: US Embassy | Belgium Embassy | Belgium color codes for nations | Passenger Locator Form

Belize

English is spoken in this Central American nation filled with wildlife spotting opportunities and stunning barrier reefs. Testing required; fully vaccinated exempt. No quarantine in place. Details and updates: US Embassy | Belize Tourism Board.

Bermuda

Bolivia

This landlocked South American country offers surreal landscapes from Andean to jungle. Testing and quarantine requirements in place. Details and updates: US Embassy.

Bosnia and Herzegovina

Bosnia and Herzegovina features cosmopolitan Sarajevo and gorgeous lakes. Testing required; quarantine is not. Details and updates: US Embassy | Bosnia Border Police

Botswana

This southern African nation is famed for its wildlife in the Okavango Delta and elsewhere. Testing and quarantine requirements are in place. Details and updates: US Embassy.

Brazil

South America's largest country has the lure of Rio's party atmosphere and the Amazon River's mystique. It also has a very high daily number of Covid-19 cases. Testing required; quarantines are not. Details and updates: US Embassy | Health declaration.

British Virgin Islands

This pretty island group lies just to the east of the US Virgin Islands in the Caribbean. Testing and quarantine requirements are in place. Details and updates: US Embassy | BVI government website | BVI Gateway website.

Bulgaria

Historic towns and natural landscapes are Bulgaria's calling cards. Testing required; exemptions for fully vaccinated or recovered from Covid-19 infection. No quarantine. Details and updates: US Embassy.

Colombia

Costa Rica

Côte d'Ivoire (Ivory Coast)

Côte d'Ivoire is a popular destination for people wanting to enjoy West African culture and food. Testing required; quarantine encouraged but not required. Details and updates: US Embassy | Travel declaration and fee.

Croatia

Croatia, the jewel of the Adriatic, is once again open to US leisure travelers. Testing required to enter; exemptions for the fully vaccinated or recovered from Covid-19 infection. No standard quarantine in place. Details and updates: US Embassy | Croatia official entry form.

Cyprus

Both parts of this politically divided Mediterranean island are open to US tourists. The Republic of Cyprus and the northern third of the island administered by Turkish Cypriots (Turkish Republic of Northern Cyprus) each have their own rules of entry and testing. Details and updates: US Embassy in Nicosia | Visit Cyprus.

Czech Republic

Denmark

Often at the top of "happiest countries" lists, Denmark now accepts US travelers only if they are fully vaccinated. Details and updates: US Embassy | Denmark tourist information.

Dominica

Dominican Republic

Dubai

Scroll down to the United Arab Emirates entry below.

Dutch Caribbean islands

Find out the important details on these various Dutch islands in the Caribbean -- renowned for their hospitality and ocean life -- by clicking on the links:

Saba: Known more for its rugged landscape and hiking than beaches, little Saba is open. Testing required. Quarantine in place; exemption for fully vaccinated. Details and updates: Saba Tourism | Saba EHAS application.

Ecuador

This Andean country at the equator also owns the Galápagos Islands in the Pacific. Testing required; fully vaccinated exempted. Quarantine required in some circumstances. Details and updates: US Embassy.

Egypt

The Nile River nation has been attracting people to see its wonders for many centuries. Testing required; quarantine is not. Details and updates: US Embassy.

Estonia

This quaint Baltic nation is now open to Americans. No testing required. Quarantine is in place, but with exceptions. Details and updates: US Embassy | Ministry of Foreign Affairs.

Ethiopia

Ethiopia has a unique and ancient culture and rugged, otherworldly landscapes. Testing and quarantine requirements are in place. Before you travel there, closely monitor news reports about violence in the northern Tigray region (video) on the border with Eritrea. Details and updates: US Embassy.

France

Fully vaccinated US leisure travelers are allowed to enter France. Testing required. Details and updates: US Embassy | France Diplomacy Twitter.

French Polynesia

French Polynesia is the idealized South Pacific destination. Testing required; quarantine in place with an exemption for the fully vaccinated. Details and updates: Islands of Tahiti | FAQ document | Online ETIS form.

Georgia

Georgia is a geographical and cultural crossroads at the Caucasus Mountains. Testing required unless you're fully vaccinated. No self-isolation for the unvaccinated under certain conditions. Details and updates: US Embassy | Georgian Ministry of Foreign Affairs.

Germany

From edgy Berlin to picturesque Bavaria, Germany is now open. Testing required; quarantine depends on vaccination status and nation from which you've arrived. Details and updates: US Embassy | German Missions in the US

Ghana

This West African cultural jewel offers historical sites, delicious food and surfing. Testing required. No quarantine. Details and updates: US Embassy.

Greece

Greece, with its many ancient ruins and islands, is now open to US travelers. Testing required; exception for the fully vaccinated. No quarantine. Details and updates: US Embassy | Passenger locator form.

Grenada

Guatemala

This Central American country offers historical sites and stunning volcano landscapes. Testing required; exceptions for the fully vaccinated or those fully recovered from Covid-19. No quarantine. Details and updates: US Embassy | Online health pass.

Honduras

Honduras has epic diving off Roatan Island and other locations. Testing required; fully vaccinated travelers are exempt. Conditional quarantine in some circumstances. Details and updates: US Embassy | Online precheck form.

Iceland

Geysers, glaciers, hot springs and waterfalls await in Iceland. You must be fully vaccinated or have proof of recovery from Covid-19 to enter. Testing and quarantine requirements in place as well. Details and updates: US Embassy | Iceland travel registration.

Ireland

Israel

From ancient Jerusalem to modern Tel Aviv, Israel now allows US tourists. Testing required. Quarantine in place for those not fully vaccinated or recovered from a case of Covid-19. You should keep a close watch on developments as you plan your trip regarding the recent conflict between Israel and Gaza. Details and updates: US Embassy | Israel Ministry of Health.

Italy

Jamaica

Jordan

Home to the amazing ruins of Petra, Dead Sea coastline and the dazzling landscape of the Wadi Rum, Jordan is open to US vacationers. Testing required; quarantine is not. Details and updates: US Embassy.

Kenya

Kenya is the definitive African safari destination, but Nairobi's urban beat attracts tourists too. Testing required; no quarantine. Details and updates: US Embassy | Trusted Travel initiative.

Latvia

Latvia -- with a walkable capital city, Art Nouveau architecture and surprising wildlife -- is open. Testing required; quarantine is not. Details and updates: US Embassy.

Liechtenstein

This tiny nation is open. Scroll to the Switzerland entry below for details.

Lithuania

This Baltic nation is made for history buffs and is open to fully vaccinated Americans only. No testing or quarantine. Details and updates: US Embassy.

The Maldives

Malta

Mexico

The land border between the US and Mexico remains closed through at least June 21, but US travelers can still fly there. No testing or quarantine requirements are in place. The US State Department lists numerous states to avoid because of crime. Details and updates: US Embassy.

Monaco

US jet-setters can visit the Mediterranean city-state if they are fully vaccinated. Testing also required. Details and updates: Embassy of Monaco.

Montenegro

This Balkan nation is allowing US travelers. Testing under most circumstances required; exceptions for the fully vaccinated or the naturally immune because of previous Covid-19 illness. Details and updates: US Embassy | Institute of Public Health of Montenegro.

Morocco

Starting June 15, this North African favorite is open leisure travelers from the United States without special invitations. Testing required, but no quarantines in place. Details and updates: US Embassy | Visit Morocco.

Namibia

US citizens can visit this southern African desert nation that appeals to adventure travelers. Testing required; quarantine is not. Details and updates: US Embassy.

Nepal

US travelers can visit the landlocked Himalayan nation. Testing and quarantine requirements in place, regardless of vaccination status. Details and updates: US Embassy.

Netherlands

US travelers can now visit Amsterdam and the rest of the Netherlands. No testing or quarantine is required as the US is deemed a safe country. Details and updates: US Embassy | Government of Netherlands

Nicaragua

Home to historical sites such as Granada and tropical beaches, Nicaragua is open. Testing required; quarantines are not. Details and updates: US Embassy | Avianca Airlines.

North Macedonia

North Macedonia has a part Balkan, part Mediterranean feel and its natural wonders are relatively unknown. No testing or quarantine required. Details and updates: US Embassy | TAV Macedonia.

Panama

Wildlife, beaches, mountain towns and a canal are Panama's calling cards. Testing required; quarantine is not. Details and updates: US Embassy | Visit Panama | Online health affidavit.

Peru

Poland

US passport holders can now see Krakow and Poland's other wonders. No testing is required, but quarantine is. Details and updates: US Embassy.

Portugal

Portugal is open to US citizens from June 15 to 27. The measure will be reviewed every two weeks and unless renewed expires midnight on June 27. Testing is required; quarantine is a possibility. Details and updates: US Embassy.

Romania

Romania offers mystique, wooded and mountainous landscapes and lots of history. No testing required. Quarantine in place with exceptions for fully vaccinated and those recovered from Covid-19. Details and updates: US Embassy | Romanian Embassy.

Rwanda

Rwanda's green hills and mountains are home to rare gorillas. Testing and quarantine requirements are in place. Details and updates: US Embassy | Visit Rwanda.

Saudi Arabia

This desert wonderland is now open. Testing required. Quarantine depends on vaccination status. Details and updates: US Embassy | Health Disclaimer.

Senegal

Senegal, known for its West African beaches and music, welcomes US tourists. Testing is required; no quarantine in place. Details and updates: US Embassy.

Serbia

Serbia is steeped in historical sites and dramatic Eastern European scenery. Testing is required but quarantines are not. Details and updates: US Embassy.

Seychelles

Slovenia

This European nation of gorgeous lakes is open only to the fully vaccinated or those recovered from Covid-19. No testing or quarantine required. Details and updates: US Embassy.

South Africa

With superb national parks, wineries and the allure of Cape Town, one of the most popular destinations in Africa is open. Testing is required; quarantine is not. Be aware some nations aren't allowing entry to tourists who have recently been to South Africa. Details and updates: US Embassy.

South Korea

From busy Seoul to relaxing Jeju Island, South Korea is open. Testing and quarantine requirements are in place. Details and updates: US Embassy | Self-diagnosis app

Spain

St. Barts

After an extended closure, this French island is allowing fully vaccinated travelers from the United States. Testing required. Details and updates: St. Barts entry protocols

St. Kitts and Nevis

This Caribbean escape allows only fully vaccinated tourists to visit. Exemptions are in place for children 17 and younger traveling with vaccinated parents. Details and updates: US Embassy | St. Kitts Tourism | Travel authorization form.

St. Lucia

Home of the steep and towering Pitons, waterfalls and volcanic beaches, the independent Caribbean nation of St. Lucia is open. Testing and quarantine requirements are in place. Details and updates: US Embassy | St. Lucia travel website.

St. Vincent and the Grenadines

Switzerland

The country's famed Alps are once again open to Americans. Testing required with exemptions for the fully vaccinated or those recovered from Covid-19. Details and updates: US Embassy | Swiss Travel Check.

Tanzania

A favorite for big-game safaris, Indian Ocean beaches and Mount Kilimanjaro, Tanzania is open. Testing required; quarantine is not. Details and updates: US Embassy | Health surveillance form.

Thailand

US passport holders can again visit this fascinating Southeast Asian destination famed for its beautiful beaches and spicy cuisine. Testing and quarantine requirements are in place. Details and updates: US Embassy | Royal Thai Embassy | Certificate of entry.

Tunisia

Tunisia offers ancient ruins, desert scenery and sunny Mediterranean beaches. Testing and quarantine requirements in place. Fully vaccinated visitors are exempt from both. Details and updates: US Embassy | Online questionnaire.

Turkey

From cosmopolitan Istanbul to rural coastal escapes, Turkey is open. Testing is required; quarantine is not. Details and updates: US Embassy | Form for entry.

Turks and Caicos

This British overseas territory northeast of Cuba and southeast of the Bahamas is known for it coral reefs, ripsaw music and low-key vibe. Testing is required; quarantine is not. Details and updates: US Embassy | Visit Turks and Caicos | Travel authorization form.

Uganda

This lush nation in Central Africa offers gorilla trekking, Nile River rafting and beautiful lakes. Testing required; quarantine is not. Details and updates: US Embassy.

United Arab Emirates

The UAE, with its glittering towers and luxury resorts, has emerged as a major world destination in the 21st century. Testing required. Quarantine protocols depend on the emirate. Details and updates: US Embassy.

United Kingdom

Leisure travel to the UK is highly discouraged but not banned. Testing and quarantine requirements are in place. Rules may vary between England, Scotland, Wales and Northern Ireland. Details and updates: US Embassy | UK government | Declaration form.

Zambia

Known for Victoria Falls and wildlife, Zambia is allowing visitors. Testing and quarantine requirements are in place. Details and updates: US Embassy.

Recently removed from the open list

The following countries had been allowing US citizens to enter but have closed again or were removed by CNN Travel for other reasons:

-- Cambodia: The US Embassy reports the Southeast Asian nation has stopped issuing tourist visas; you can still apply for business-linked visas.
-- Chile: It has closed its borders to almost all tourists through June 30.
-- Sri Lanka: No international flights allowed until June 1.

Omitted countries

This is a curated list and not a full listing. CNN Travel has omitted certain open countries if they had very limited numbers of US travelers before the pandemic; have ongoing or recent armed conflicts, terrorism or rampant crime and unrest; or have entry requirements so extensive and complicated that they put the country out of reach of almost all US citizens. However, you can click here to check for the status and entry requirements of any country or territory in the world you wish to visit.