The U.S. Senate Foreign Relations Committee is expected to vote Tuesday on whether to approve John Bolton, President Bush's controversial pick for ambassador to the United Nations.

Opposition Democrats want to delay the vote so they can further investigate allegations that Mr. Bolton threatened subordinates and withheld information from superiors in his role as undersecretary of state for arms control.

But committee chairman Richard Lugar said in a statement today that it is time for the panel to make a decision. He said the concerns raised about Mr. Bolton do not warrant rejection of the nomination. Mr. Bolton has denied the allegations.

Republicans control the committee by a 10-to-eight margin. If approved by the committee, Mr. Bolton's nomination goes to the full Senate for a vote.

Some information for this report provided by AP and Reuters.