19 U.S.C. § 4432: Establishment of preclearance operations

Pursuant to section 1629 of this title and section 1103(a)(7) of title 8, and provided that an aviation security preclearance agreement (as defined in section 44901(d)(4)(B) of title 49) is in effect, the Secretary may establish and maintain U.S. Customs and Border Protection preclearance operations in a foreign country—(1) to prevent terrorists, instruments of terrorism, and other security threats from entering the United States; (2) to prevent inadmissible persons from entering the United States; (3) to ensure that merchandise destined for the United States complies with applicable laws; (4) to ensure the prompt processing of persons eligible to travel to the United States; and (5) to accomplish such other objectives as the Secretary determines are necessary to protect the United States.