The main purpose of this legislation is to strengthen the United States' immigration enforcement by denying entry to individuals who are subject to specific sanctions. These sanctions are outlined in Executive Order 13876, which relates to actions against Iran. The goal is to enhance national security and ensure that individuals who may pose a threat to the U.S. are not allowed to enter the country. Key provisions of the legislation include a requirement that individuals who are subject to sanctions under Executive Order 13876 will be denied visas to enter the United States.