Sen. Biden of Delaware, the senior Democrat on the committee, read from a letter [Melody Townsel, a former contract worker for the United States Agency for International Development] had sent the committee, although he did not name her.

Ms. Townsel, whose allegations had begun to emerge in the news media , has said that for two weeks in 1994, when Mr. Bolton was working as a private lawyer for a subcontractor that clashed with her employer, he harassed her in a Moscow hotel, falsely claiming that she had misused funds and could face jail.

"'Mr. Bolton,'" Mr. Biden read from the letter, "proceeded to chase me through the halls of a Russian hotel, throwing things at me, shoving threatening letters under my door, and genuinely behaving like a madman. I eventually retreated to my hotel room and stayed there. Mr Bolton then routinely visited me to pound on the door and shout threats.'"

Senator Harry Reid, the Democratic leader, said today that Mr. Bolton's alleged comments to Ms. Townsel about possibly facing jail were "absolute lies."