As Europe announced this week that it is rolling out the welcome companion to U.S. citizens this northern summer, transatlantic air traffic is expected to rebound. While details are yet to be worked out (i.e. set firm reopening dates), the move will be welcomed by airlines and travelers alike.

But it’s not just Europe that is opening its borders to American citizens this summer. More and more countries are welcoming US citizens. It should be noted that very few countries will allow you to just introduce yourself and introduce yourself. Traveling in 2021 means you will invariably need to be vaccinated and provide proof of it.

It is a dynamic situation. Travelers should be fully aware of a country’s entry requirements. Most airlines will not let you board unless you meet the entry requirements of the destination country.

The following list of countries that allow vaccinated U.S. travelers is correct at the time of posting. It is subject to change.

Europe should open to American citizens this summer

This week, the 27 member countries of the European Union officially decided to allow entry of vaccinated travelers without quarantine if they come from countries deemed safe. Currently, the United States falls into this “safe” category. However, individual EU countries do not yet have fixed start dates. The UK allows travelers from the US to enter. However, the UK continues to enforce a 10-day self-funded hotel quarantine, vaccinated or not.

Countries like Greece, Croatia, Bulgaria, Austria, Italy, Romania, Moldova, Albania, San Marino and Ukraine allow or are about to allow entry of US citizens vaccinated without quarantine. Entry requirements vary, so stay informed before you travel. For example, many of these countries require a full vaccination at least 14 days before entry.

Several Central and South American countries open to American travelers

In the Caribbean, several countries welcome American citizens subject to certain rules. These countries include Anguilla, Aruba, the Bahamas, Bonaire, Bermuda, Curaçao, Haiti, Jamaica, Saint Barthélemy, Saint Martin, Puerto Rice, and the US Virgin Islands.

In Central America, Costa Rica, Nicaragua, Panama, Belize, El Salvador, and Guatemala all allow entry from the United States without quarantine subject to certain conditions. This is good news for airlines with strong networks in Central America, such as American Airlines. In addition, with good timing, Alaska Airlines will soon launch a new service to Belize from the west coast.

In South America, there are fewer options. Brazil, Guyana, Paraguay, Ecuador, and Venezuela allow all vaccinated (and in some cases unvaccinated) travelers from the United States to enter the United States subject to each country’s rules. Venezuela, for example, imposes visas on American citizens.

Africa opens to US citizens, Asia and the Pacific remain largely closed

Around the Middle East and across North Africa, Israel, Lebanon, Bahrain, Egypt, Morocco, Iraq and Djibouti will allow vaccinated US citizens to enter. Again, the rules vary. For example, in Morocco, travelers must stay in an approved hotel or resort. Further south, a multitude of countries will allow vaccinated travelers to enter without quarantine. These countries include Benin, Botswana, Burkina Faso, Cameroon, Cape Verde, Côte d’Ivoire, Democratic Republic of Congo, Ghana, Guinea, Kenya, Lesotho, Liberia, Mali , Malawi, Mozambique, Namibia, Seychelles, Senegal, Somalia, South Africa, Sudan, Tanzania, Togo and Uganda.

In the stans part of the world, Armenia, Kyrgyzstan, Tajikistan, Turkey, Uzbekistan and Georgia allow vaccinated travelers from the United States not to be quarantined.

Across Asia and much of the Pacific, options for U.S. citizens, vaccinated or not, are far fewer. Singapore allows vaccinated travelers from the United States if they have a secure travel pass. It’s a similar situation in the Maldives. Guam is open to US citizens, but Guam is also US territory. Many countries in Asia will allow entry if you are prepared to quarantine. But countries like Japan, Indonesia, Australia, New Zealand, and Fiji are all largely closed to US citizens.

Borders are slowly opening, but the majority remain closed to American travelers

Canada, a neighboring country, is also closed to daily travel from the United States. While the list of countries that US citizens can fly to grows, the majority of countries remain mostly banned. The US State Department is also warning its citizens not to travel to most countries. This, in turn, impacts travel insurance and limits people’s willingness to board a flight. But as the recent decision of the European Union attests, more and more travel opportunities are opening up. Borders may be slowly reopening, but the trend is in the right direction.