The move came after a key Republican senator branded Bolton - President George Bush's handpicked nominee - as unfit for the job and the panel decided not to endorse his nomination.

While the committee action advanced Bolton's nomination, Republican Senator George Voinovich's stinging criticisms of Bush's choice for the UN position gave Democrats more ammunition to fight his confirmation in the full Senate.

Bolton's prospects were good in the Senate, which Republicans control 55-45. But Voinovich's defection was an embarrassment for Bush.

The committee on Thursday voted 10-8, along party lines, to advance the nomination. Democrats argued that the committee should reject Bolton and force Bush to find a better candidate.

The White House said it was confident the Senate would back Bolton, who Bush has touted as the best choice to push for reforms at the world body.

"We respect Senator Voinovich's decision, but there are many people who agree with the president that John Bolton is the right person at the right time for this important position," spokesman Scott McClellan said.

Republican criticism

Voinovich blasted Bolton as "the poster child of what someone in the diplomatic corps should not be".

President Bush insists Bolton is
the best candidate for the UN

"The United States can do better than John Bolton," the Ohio senator said. He said the blunt-spoken Bolton could worsen the United States' already poor image around the world.

Voinovich later said he thought Bolton's confirmation was in some doubt when it reaches the full Senate. "No one is really excited about him," he said.

Democrats contend that in his role as top US diplomat for arms control, Bolton tried to coerce intelligence analysts to conform to his hardline views, bullied subordinates and had a chilling effect on the intelligence community.