U.S. Ambassador John R. Bolton said Thursday that inaction by U.N. members is jeopardizing the passage of U.S.- and U.N.-backed initiatives to combat human rights abuses and streamline the agency's bureaucracy.

Bolton, speaking at a luncheon hosted by the Foreign Policy Association, hinted that Congress may retaliate against the United Nations if it failed to take steps toward improving the way it conducts business. He later told the General Assembly that the United States would oppose any effort to expand the Security Council beyond 20 members and would insist that states meet criteria -- including a commitment to democracy and a record of combating terrorism -- to become permanent members.

"The United States supports an expansion of the Security Council that can contribute to its strength and effectiveness," Bolton told the 191-member General Assembly. "We must . . . ensure that new permanent members are supremely qualified to undertake the tremendous duties and responsibilities they will assume."

Together, Bolton's two speeches signaled growing U.S. frustration with the sluggish pace and direction of change in the organization in the weeks since more than 150 world leaders met in New York to discuss proposed changes. In particular, Bolton faulted his counterparts with failing to make progress on two U.S. priorities -- the establishment of a new human rights council that excludes rights abusers and the creation of an independent audit board to monitor U.N. spending.

"We are in jeopardy of not seeing it enacted," he told the luncheon gathering of diplomats, executives and foreign policy specialists at Manhattan's St. Regis Hotel.

In his most critical assessment of the agency since becoming ambassador to the world body, Bolton said the broader U.N. membership has not recognized the urgency of approving administrative changes designed to restore the organization's credibility, which has been tarnished by revelations of corruption in the oil-for-food program and reports of widespread sexual abuse by U.N. peacekeepers.

The scandals "did not arise out of thin air," Bolton said. "The mismanagement and the corruption that we have seen in the program came out of an existing culture on First Avenue," where U.N. headquarters is located. Bolton said "it's hard to have conversations" with his colleagues about the extent of "mismanagement and corruption" uncovered by former Federal Reserve chairman Paul A. Volcker, who recently ended an 18-month inquiry into abuses in the United Nations' largest humanitarian program.

Bolton said U.N. members will be confronted with heightened congressional scrutiny if they fail to reform the agency. "When you don't feel a sense of movement and progress toward solving the problem -- if I can say it's an American national characteristic to solve problems and not massage them -- we're going to have increasing difficulties."

In his subsequent address to the General Assembly, Bolton dismissed a new initiative by Switzerland, Singapore, Jordan, Costa Rica and Liechtenstein to change Security Council procedures.

The proposal would grant the wider U.N. membership a greater say in council decisions. It would also call on the council's five permanent members -- the United States, Russia, China, France and Britain -- to agree never to cast a veto in cases where forceful council action could halt genocide or other crimes against humanity.

"We believe that, as clearly stated in the [U.N.] Charter, the Security Council alone will determine its own working methods and procedures," he told the assembly.

Bolton also said the United States would oppose initiatives by the African Union, and by the four governments seeking permanent Security Council membership -- Japan, India, Brazil and Germany -- to renew their bids to expand the group to as many as 24 members. The two groups want the General Assembly to vote on the initiatives.