The White House renewed its insistence yesterday that the Senate confirm John R. Bolton to be U.N. ambassador, but key senators said they see no evidence of a plan to make it happen.

With the Senate having voted twice to sustain a filibuster against Bolton, the Bush administration and congressional leaders appeared to assign each other the responsibility of breaking the three-month impasse. Several senators said they do not understand why President Bush is demanding Bolton's approval without presenting a strategy for picking up the handful of needed Democrats.

"I don't see anything happening," said Sen. Joseph R. Biden Jr. (Del.), a Democratic leader of the Bolton fight. "I think the train has left the station" in terms of finding a compromise.

Senate Majority Leader Bill Frist (R-Tenn.) largely washed his hands of the matter, saying he has done all he can to secure the 60 votes needed in the 100-member chamber to end debate and allow a simple-majority vote on Bolton's confirmation, which he predicted would pass. "The environment has to change, but it's not just up to the White House," Frist said in an interview. "It's really between the White House and Chris Dodd and Joe Biden."

Dodd (D-Conn.) and Biden have led their party's opposition to Bolton, a combative former State Department official who is championed by many conservatives and strenuously opposed by liberals. Dodd's staff said yesterday that he, like Biden, had received no new overtures from the White House.

Senators and aides said administration officials have two options in trying to placate Democrats who are demanding documents related to Bolton's State Department work. They can seek an accord with Biden and Dodd, who wield substantial influence on the matter, the sources said. Or they can bypass party leaders and try to cut separate deals with a few moderate Democrats.

A similar strategy was used last month when seven Republicans and seven Democrats, working outside leadership circles, reached a deal on judicial filibusters, White House spokesman Scott McClellan said Tuesday. But some Democrats involved in that pact said yesterday the White House has not approached them about Bolton -- and such efforts would be useless, anyway.

"This is not a situation that can be resolved in that manner," said Sen. Daniel K. Inouye (D-Hawaii), who signed the deal on judges. Bush's refusal to provide the Bolton-related documents, he said, "is insulting to the Senate."

Another Democratic signer of the judicial pact, Sen. Ken Salazar of Colorado, said in an interview that "the president briefly talked to me" about Bolton last week in a conversation that touched "on a variety of issues." Salazar said he would support Bolton only if the administration provides the disputed documents.

Sen. Ben Nelson (Neb.), a key player in the judicial compromise, is one of three Democrats who have voted to end the Bolton filibuster. The so-called Gang of 14 met recently for breakfast, he said, but their only goal is to stick together on judicial matters. "I haven't seen any evidence" of an effort to strike a similar bipartisan accord on Bolton, he said.

Secretary of State Condoleezza Rice, attending a European meeting on Iraq, told CNN yesterday that she continues to press for a confirmation vote for Bolton. "I am concentrating now, and I've been on the phone even here from Europe with people back in Washington, let's get the vote," Rice said. "We have answered countless inquiries," and no more are needed, she said. She brushed aside questions on whether Bush might bypass Congress and give Bolton a recess appointment, which would last 18 months.

McClellan told reporters yesterday that the administration has supplied all the documents on Bolton that are justified. "So I think it's clear the Democratic leadership is not interested in working in good faith and finding the middle ground," he said.

Sen. Trent Lott (R-Miss.) said Bush should provide the disputed documents, calling his refusal to do so "a very thin-reed principle." Lott said it would be hard for Bush to cut a separate deal with centrist Democrats because "there's no incentive for them" to buck their party's leaders to seat a highly contentious nominee to the United Nations.

Sen. John W. Warner (Va.), a GOP signer of the agreement on judges, said yesterday he would intervene in the Bolton matter only if Frist makes clear he wants a third vote to try to end the filibuster. "I am one of those senators who have quietly crossed the aisle to try to get support for John Bolton," Warner said in an interview. "It's a leadership decision to bring this back for a vote. If our leader announces one, I will continue quietly to do that type of work."

Majority Leader Bill Frist said the White House must deal with duo.