President Donald Trump announced Wednesday he was "starting the process of terminating the diversity lottery program" that he said allowed the suspected New York City attacker to enter the United States legally, and that he would ask Congress to "get rid" of the program immediately.
Why does the U.S. have this program in the first place?
Its origins stem from the 1990 Immigration and Nationality Act, which was signed by Republican President George H.W. Bush.
What are the eligibility requirements?
The suspect Sayfullo Saipov, 29, entered the U.S. via the State Department's diversity immigrant visa program, which requires the applicant to be a native of a qualifying country. The applicant also must have completed high school or "two years of work experience within the past five years in an occupation that requires at least two years of training or experience to perform," according to the State Department.
What's the vetting process?
Those selected through this program must go through all of the same background checks and screening processes as any other immigrant visa applicant to be granted admission, including document presentation, background checks, in person interviews and medical exams.