Washington ? President Bush prodded the Senate on Thursday to confirm John Bolton as U.N. ambassador and blamed politics for holding up the vote.

Two days after the Republican-led Senate Foreign Relations Committee abruptly postponed plans to vote on the nomination, Majority Leader Bill Frist, R-Tenn., said he strongly supported Bolton, but “I can’t speak for all of leadership” of the Senate GOP.

No top Senate Republican has voiced opposition to Bolton. But cracks in support by some GOP senators have put the nomination in question. The White House is lobbying three Republicans on the committee whose concern about Bolton’s nomination derailed Tuesday’s planned vote. Their worries have set in motion three more weeks of investigation into how Bolton treated subordinates who disagreed with his views.

Before speaking to a meeting of insurance agents about Social Security, Bush described Washington as a place where “sometimes politics gets in the way of doing the people’s business.”

“John’s distinguished career and service to our nation demonstrates that he is the right man at the right time for this important assignment,” Bush said.

As it resumed research on Bolton, the Senate committee received a new accusation of abusive behavior by the nominee, according to a Democratic committee staff member.