22 C.F.R. § 41.71 Transit aliens.
(a) Transit aliens—general. An alien is classifiable as a nonimmigrant transit alien under INA 101(a) (15) (C) if the consular officer is satisfied that the alien:
(1) Intends to pass in immediate and continuous transit through the United States;
(2) Is in possession of a common carrier ticket or other evidence of transportation arrangements to the alien's destination;
(3) Is in possession of sufficient funds to carry out the purpose of the transit journey, or has sufficient funds otherwise available for that purpose; and
(4) Has permission to enter some country other than the United States following the transit through the United States, unless the alien submits satisfactory evidence that such advance permission is not required.
(b) Certain aliens in transit to United Nations. An alien within the provisions of paragraph (3), (4), or (5) of section 11 of the Headquarters Agreement with the United Nations, to whom a visa is to be issued for the purpose of applying for admission solely in transit to the United Nations Headquarters District, may upon request or at the direction of the Secretary of State be issued a nonimmigrant visa bearing the symbol C-2. If such a visa is issued, the recipient shall be subject to such restrictions on travel within the United States as may be provided in regulations prescribed by the Secretary of Homeland Security.