Mr. Bush has the power to fill vacancies without Senate approval while Congress is in recess. Under the Constitution, a recess appointment during the lawmakers' August break would last until the next session of Congress, which begins in January 2007.
An end run around the Senate confirmation process would certainly annoy senators particularly Democrats at a time when Mr. Bush's nomination of John Roberts to serve on the Supreme Court hangs in the balance. It also could hamper Bolton at the United Nations, by sending him there as a short-timer without the Senate's backing.
"There's just too much unanswered about Bolton and I think the president would make a truly serious mistake if he makes a recess appointment," Sen. Joseph Biden of Delaware, the top Democrat on the Foreign Relations Committee, said in an interview.
Two officials, speaking on condition of anonymity because the president had not made the announcement and Congress wasn't yet in recess, said the president planned to exercise that authority before he leaves Washington on Tuesday for his ranch. The House recessed on Thursday and the Senate's break was scheduled to begin later Friday.
CBS News Correspondent Mark Knoller reports that CBS News also was told Bush intends to use a recess appointment in the coming days to make John Bolton the U.S. ambassador to the United Nations.
Earlier in the day, White House press secretary Scott McClellan gave the strongest indication yet that Bush planned to do so, noting that the U.N. General Assembly has its annual meeting in mid-September.
"It's important that we get our permanent representative in place," he said. "This is a critical time and it's important to continue moving forward on comprehensive reform."
Mr. Bush counselor Dan Bartlett said the president had not made a decision on whether to make a recess appointment.
"He retains that right to do, but he will continue to work with the Senate as long as he can," Barlett said. "But he has not made a decision."
Bolton's nomination, announced in March by the president, was controversial from the start and has been stalled in the Senate by Democrats.
Critics say Bolton, who has been accused of mistreating subordinates and has been openly skeptical about the United Nations, would be ill-suited to the sensitive diplomatic task at the world body. The White House says the former undersecretary of state for arms control, who has long been one of Bush's most conservative foreign policy advisers, is exactly the man to whip the United Nations into shape.
This week, critics raised a fresh concern, saying Bolton had neglected to tell Congress he had been interviewed in a government investigation into faulty prewar intelligence on Iraq.
The State Department said Thursday that Bolton was interviewed in 2003 by the department inspector general. The office was conducting a joint investigation with the CIA into allegations that Iraq attempted to buy nuclear materials from Niger. Bolton had earlier submitted a questionnaire to the Senate in which he had said he had not testified to a grand jury or been interviewed by investigators in any inquiry over the past five years.
Republican Sen. Lincoln Chafee said he would vote against Bolton if given the chance and would oppose a recess appointment if it is accurate that Bolton's form was originally incorrect. "Any intimidation of the facts, or suppression of information getting to the public which led us to the war, absolutely should preclude him from a recess appointment," said Chafee, of Rhode Island.
Also Friday, 35 Democratic senators and one independent, Sen. Jim Jeffords of Vermont, sent a letter to Mr. Bush urging against a recess appointment. "Sending someone to the United Nations who has not been confirmed by the United States Senate and now who has admitted to not being truthful on a document so important that it requires a sworn affidavit is going to set our efforts back in many ways," the letter said.