Democrats in the US Senate have managed to delay a vote on President George W Bush's controversial nomination for UN ambassador, John Bolton.
President Bush thinks Mr Bolton will "get the job done"
The Democrats said they had not been able to access all the classified documents they required.
The vote is now expected to take place in June. It follows the Senate Foreign Relations Committee's failure to back Mr Bolton two weeks ago.
He has been accused by opponents of bullying and arrogance.
The White House says the charges are unfounded.
Mr Bush has called Mr Bolton "a blunt guy" who "can get the job done at the United Nations".
Some 56 senators voted to end the debate and take an immediate poll on Mr Bolton's confirmation, four short of the required 60 votes. A total of 42 senators voted against.
Democrats earlier made a final request that the White House release documents which they say will reveal whether Mr Bolton tried to influence intelligence assessments of Syria and sought to find out the names of government officials who opposed him.
"We are willing to vote 10 minutes after we get back in session, if in fact they provide the information," Senator Joseph Biden said.
White House spokesman Scott McClellan criticised Democrats for the latest delay.
"This is a nominee that enjoys majority support," he said.
Republicans were thought to have been likely to win the vote.
But at least one Republican senator had said he would vote against the nominee.
George Voinovich of Ohio refused to endorse Mr Bolton in the committee, and has been lobbying colleagues in the full Senate to vote against him.
The senator urged colleagues to consider his record, and not vote for him simply out of loyalty to the president.
The Senate Foreign Relations Committee voted along party lines to send the nomination to the full Senate, but without a recommendation.
Correspondents say it is highly unusual for a committee where the president's party is in the majority to fail to support one of his nominations for office.