Representative Les Aspin, a Wisconsin Democrat who is chairman of the House Armed Services Committee and is leading the Congressional visit to the Soviet Union, also is a top traveler.

Asked about the Qaeda leader's whereabouts during a Congressional visit to Islamabad in September 2009, the Pakistani interior minister, Rehman Malik, replied that he "'had no clue," but added that he did not believe that Bin Laden was in the area.

So long as Mr. Bush continues to shun high-level discussions with this troublesome but strategically located neighbor of Israel, Lebanon and Iraq, such Congressional visits can serve the useful purpose of spurring a much needed examination of the administration's failed policies.

The duration and scope of Congressional visits are tightly controlled.

The stop was part of their Congressional visit to Vietnam, China and Japan to discuss economic and security issues.

In recent years, Mr. Messing's organization has sponsored more than a dozen Congressional visits to Central America in conjunction with the State Department.

Mr. Hinchey's lawyer, David Lenefsky, said his client - who he said was on a Congressional visit to Germany yesterday - had no knowledge of the 1992 transaction.

He said lawmakers had already adjusted their schedule once to avoid conflicting with another Congressional visit to Iraq in an effort not to strain American officials and troops.

Although the family has few holdings in the United States, it has been active in cultural and political exchanges and was among the founders of the United States-Indonesia Society, which has sponsored Congressional visits to Indonesia.

Mrs. Kanchanalak's influence in Washington grew to the point that she knew about impending Congressional visits before the United States Embassy in Bangkok, said one diplomat here.