Applying abroad at a United States consulate or embassy
When you are not in the United States, and a family member or employer is petitioning for your permanent resident or non-immigrant visa, you have to pass through the United States consulate in another country. The consulates, depending on what country you are in, are notoriously difficult to communicate and cooperate with. For this reason, the consular process is one of the most difficult aspects of immigration law.
Usually, your case has traveled a long way to make it to the consulate in your country. It likely started with a petition here in the United States, then it moved to the National Visa Center, then finally, if you were lucky, it made it to the consulate. Your case must be filed correctly with all appropriate evidence and information before it gets to the consulate, because some errors could lead to a denial, and a denial at the consulate is non-reviewable.
The consular interview
An individual interview at the consulate is also almost always necessary. A consular officer will go over the petition that your family member or employer filed for you, then they will review the visa application and the evidence with you. Finally, if the consular officer is satisfied with your interview, you will turn in your passport. It will soon be returned to you with your visa permanently printed inside, and you will be allowed to come to the United States.
Consulates are not nice places for lawyers; sometimes we are not even allowed to go into the interview with our clients. Still, if you have a lawyer that will prepare adequate petitions, applications, and evidence for you, nothing can stop you when you attend your interview. It is of the highest importance to have a lawyer help you with the consular process.