The US Senate Committee on Foreign Relations has been forced to delay a vote on President George W Bush's nominee as UN Ambassador, John Bolton.
The delay occurs in order to examine new allegations against Mr Bolton of bullying behaviour towards junior staff.
The committee agreed to postpone the vote until next month after a Republican Senator, George Voinovich from Ohio, said he was not yet prepared to vote for Mr Bolton.
Proceeding with the vote could have led to a tie that would have prevented the nomination from going to the full senate.
President Bush nominated Mr Bolton, who has been an outspoken critic of the UN, for the post last month. US Secretary of State Condoleezza Rice said Mr Bolton would be a strong voice for reform at the world body.
However, Democrats say there were fresh accusations that suggested Mr Bolton had displayed a pattern of abusive behaviour toward subordinates, and tried to force intelligence analysts into writing their analyses to suit his views.
