The standard recommendation or requirement that foreign nationals obtain their U.S. visas (whether temporary, nonimmigrant visas or immigrant visas for permanent residence) can pose a difficulty to citizens of countries where the U.S. has no diplomatic presence, or where the U.S. diplomatic mission has limited or suspended its activities. This can happen due to diplomatic issues, security concerns, natural disasters, geographic convenience, or other reasons.
The State Department sometimes maintains special websites as "virtual" diplomatic missions to countries or territories where it has no physical posts, but while these often provide valuable information, they do not usually enable remote visa services, or otherwise substitute for actual embassies or consulates.
Here, we'll take a look at the alternatives for visa seekers who need a live, in-person services from a U.S. embassy or consulate.
People who wish to enter the U.S. as nonimmigrants (on temporary visas such as an F-1, B-1 or B-2, or H-1B) are often allowed to apply for their visas at any U.S. embassy or consulate. While doing so outside one's home country is not usually recommended, it is an option for people with no other realistic choice. You'd want to pick the most logical one, whether it's near where you live or a place that you're traveling through anyway.
By contrast, foreign nationals who wish to enter the United States as new permanent residents (new green card holders) are usually required to attend a personal interview and obtain their immigrant visa at a U.S. embassy or consulate in their country of citizenship or last residence. Fortunately, the U.S. State Department (the agency that oversees U.S visa processes) can accommodate immigrant-visa seekers from countries lacking U.S. consular services, typically by processing their applications at U.S. embassies or consulates in neighboring states (although limited in-country services might still be provided, sometimes through third-country embassies).
Less fortunately, however, this type of accommodation often entails additional barriers related to travel. This might include visa requirements for access to host states as well as costs of transportation and extended stays on foreign land.
A long-term problem for some visa seekers is when the U.S. has no diplomatic relations with the country in question at all. The U.S. typically extends diplomatic relations to countries whose "sovereignty" it legally recognizes, and withholds diplomatic presence from territories with which it does not enjoy normal relations. There are important exceptions, however.
A few countries hold no official diplomatic relationship with the United States, including Bhutan, Iran, and North Korea. Citizens of all three countries have nonetheless been allowed to process their U.S. immigrant visa applications in nearby countries: India for citizens of Bhutan; Turkey, the United Arab Emirates, and Armenia for citizens of Iran; and China for citizens of North Korea (in rare cases such as for visits to the United Nations).
So, for example, immigrant-visa seekers from Iran would need not only to appear for an interview but also to complete other application-related requirements (such as a medical examination) in one of the three designated countries. (Note that each post may impose very different scheduling procedures when it comes to interviews for nonimmigrant visas.)
In 2015, the U.S. government began reestablishing direct diplomatic relations with Cuba, and now has an embassy in Havana. For many years before that, an indirect presence (an "Interests Section") had been maintained in the country's capital through the Swiss Embassy.
The U.S. government sometimes maintains consulates in territories that it does not, for one reason or another, formally recognize as sovereign. For a time, stateless Palestinians could process their immigrant visa applications at the U.S. Consulate General in Jerusalem, but the Trump Administration closed this consulate.
There are also contested territories where the U.S. has created special organizations to provide consular and other quasi-diplomatic services. This has been the case, for example, in Taiwan; an island claimed by China and no longer officially recognized as independent by the U.S. after 1979. The U.S. has nonetheless continued after that date to offer visa services inside the territory through a special not-for-profit organization: the American Institute in Taiwan.
There are countries that enjoy full diplomatic relations with the U.S., but where, mainly for reasons of geographic convenience, the U.S. does not maintain any diplomatic presence. These include the African state of Guinea-Bissau, Grenada, Saint Lucia, and other small Caribbean islands.
Residents of these nations are advised to apply for their immigrant visas at U.S. embassies in designated nearby countries: Senegal for Guinea-Bissau, and Barbados or the Bahamas for the various Caribbean islands.
Finally, there are countries where the U.S. has an official diplomatic presence but also where, due to country and international conditions (insecurity, political conflict, or natural disasters), visa services have been suspended or limited.
For example, immigrant-visa seekers from Yemen are likely to be scheduled to appear for their interview at the U.S. embassy in Egypt, Djibouti, Saudi Arabia, Malaysia, or Oman.
Similarly, applicants from Russia have recently been processed at U.S. consulates in Germany and Poland, applicants from Libya have recently been processed at the U.S. Consulate in Morocco, applicants from Syria have been processed at the U.S. embassy in Jordan, and applicants from Somalia have been processed at the U.S. embassies in Kenya, Jordan, and Djibouti.
See the U.S. State Department website for a list of consulates and embassies serving each country, and visit the website of the U.S. consulate (or virtual consulate) serving your country for further information. Also, you could make your life easier by hiring an experienced immigration attorney to handle your visa case. Because immigration law is federal, an attorney in any U.S. state can help you (though it would make most sense to hire one in the state you plan to live or visit).