To request from certain countries information concerning American servicemen and civilians missing in Southeast Asia during the Vietnam conflict and to require the heads of Federal departments and agencies to disclose to Congress information concerning such servicemen and civilians.

Requires the President to: (1) request from Bulgaria, Cambodia, China, Czechoslovakia, Hungary, Laos, Mongolia, North Korea, Poland, Romania, the Soviet Union, Vietnam, and any successor state of such countries information those countries may possess concerning American military and civilian personnel who were killed in action or listed in a missing status or as deserters or defectors in Southeast Asia during the Vietnam conflict; (2) deliver such information to the Congress in response to a request; and (3) direct the Directors of the Central Intelligence Agency, the Defense Intelligence Agency, and the National Security Agency to provide information in their possession concerning such individuals to the Congress so that the Congress will be able to properly evaluate information from such countries.

Prohibits, if the Congress determines by joint resolution that a country has not made a good faith effort to reply to the President's request: (1) economic assistance to the country until it complies with this Act's requirements; (2) most-favored-nation treatment of the country's products; (3) participation by the country in any program under which the United States extends credit or credit or investment guarantees; and (4) any commercial agreement between the country and the United States from taking effect.