The Senate Foreign Relations Committee was expected to vote Tuesday on the nomination of Bolton, a sharp-tongued conservative known for using brusque language to describe the U.N. and individual nations.
The meeting came amid complaints from Democrats that they did not have enough time to investigate the latest in a string of allegations against Bolton. Democrats on the panel had repeatedly asked for delays in the vote.
A spokesman for committee chairman Richard Lugar, R-Ind., said Lugar saw no reason to delay the vote.
"I do not think the concerns raised about Secretary Bolton warrant our rejection of the president's selection for his own representative to the U.N.," Lugar said in a statement prepared for Tuesday's session.
White House press secretary Scott McClellan said there was no need for delay.
Asked if the president had any reservations about Bolton's fitness for the post, McClellan replied: "Absolutely not."
Bolton has addressed all questions about his record and behavior by testifying before the committee and offering additional answers to the panel in writing, McClellan said.
Democrats hoped to defeat Bolton but were outnumbered 10-8 on the committee.
Several Republicans have made it clear they have reservations, that the president could have chosen someone better for the post, but it would be extraordinary for a Republican to vote against one of the Mr. Bush's nominees, reports CBS News Capitol Hill Correspondent Bob Fuss.
At least one Democratic senator, Sen. Christopher J. Dodd, D-Conn., said he would ask for a closed session so the committee could hear from intelligence officials about information Bolton requested relating to National Security Agency communications.
According to a spokesman for Dodd, Bolton asked for and received the identities of 10 U.S. officials involved in such secret NSA interceptions during the past four years.