President Bush bypassed Congress Monday and appointed John Bolton (search) to be the next U.S. ambassador to the United Nations.

"This post is too important to leave vacant any longer, especially during a war and a vital debate about U.N. reform. So today I've used my constitutional authority to appoint John Bolton to serve as America's ambassador to the United Nations (search)," Bush said, with Bolton at his side, during an announcement in the Roosevelt Room of the White House.

"I am sending John to the U.N. with my complete confidence ... His mission now is to speak for me on critical issues facing the international community. And he'll make it clear that America values the potential of the United Nations to be a source of hope and dignity and peace," Bush said.

"I am profoundly grateful and deeply humbled," Bolton said. "It will be a distinct privilege to be an advocate for America's values and interests at the U.N."

Within five hours of his appointment, Bolton had been sworn in and arrived at the U.S. mission in New York to begin work. He refused to speak with reporters.

After months of foundering, Bolton is headed up to the United Nations with the blessing of the president, but without confirmation from the Senate after Democrats twice blocked a vote.

For four months, Senate Democrats questioned Bolton's temper and treatment of staff aides. They also said they need more documents relating to Bolton's term as undersecretary for arms control and international security.

The anti-Bolton push ramped up again last week when it was revealed that Bolton answered a question inaccurately on a form submitted to the Senate in March. The State Department was forced to correct it after first saying that Bolton had not mistakenly denied that he discussed the leak of a CIA agent's name with the State Department inspector general.

After Bush's appointment, Democrats have not relented in their argument that Bolton is not the man for the job.

"At a time when we need to reassert our diplomatic power in the world, President Bush has decided to send a seriously flawed and weakened candidate to the United Nations," said Senate Democratic Leader Harry Reid of Nevada. "The reason Bolton is being recess appointed is because the president chose to stonewall the Senate. Mr. Bolton could have had his up or down vote had President Bush given senators the information they needed. Instead, Bolton arrives at the United Nations with a cloud hanging over his head."

On Monday, Sen. Christopher Dodd, D-Conn., who helped lead the Democratic charge against Bolton, released a statement expressing his continued opposition.

"The president has done a real disservice to our nation by appointing an individual who lacks the credibility to further U.S. interests at the United Nations. I will be monitoring his performance closely to ensure that he does not abuse his authority as he has in the past," he said.

During confirmation hearings, one Republican senator, George Voinovich (search) of Ohio, blasted Bolton's selection and described him as "the poster child of what someone in the diplomatic corps should not be." Voinovich prevented a favorable recommendation to emerge for Bolton out of the Senate Judiciary Committee, which has a 10-8 advantage of Republicans over Democrats.

"I am truly concerned that a recess appointment will only add to John Bolton's baggage and his lack of credibility with the United Nations," Voinovich said in response to Bush's move.

In naming Bolton to the post, Bush specifically commented on moves by some lawmakers to prevent a vote on Bolton.

"Because of partisan delaying tactics by a handful of senators, John was denied the up or down vote that he deserves," Bush said Monday.

A recess appointment is a procedure that allows a president to fill a vacant job when Congress is not in session. Lawmakers left for vacation last week. The move will allow Bolton to stay in the job without Senate confirmation until the end of the current Congress in January 2007.

After the announcement, U.N. Secretary-General Kofi Annan said the manner in which Bolton was given the post will not affect their working relationship.

"It is the president's prerogative and the president has decided to appoint him through this process for him to come and represent him. And from where I stand, we will work with him as the ambassador and representative of the president and the government," Annan said in a morning press conference.

"We look forward to working with him, as I do with the other 190 ambassadors, and we will welcome him at a time when we are in the midst of major reform," Annan said.

Bolton's is the 110th recess appointment for Bush. Former President Clinton made 140 recess appointments during his two terms in office.

During confirmation hearings, questions circled around allegations that Bolton abused underlings or tried to browbeat intelligence analysts whose views differed from his own. Witnesses told the committee that Bolton lost his temper, tried to engineer the ouster of at least two intelligence analysts and otherwise threw his weight around. But Democrats were never able to establish that his actions crossed the line to out-and-out harassment or improper intimidation.

Separately, Democrats and the White House deadlocked over Bolton's acknowledged request for names of U.S officials whose communications were secretly picked up by the National Security Agency. Democrats said the material might show that Bolton conducted a witch hunt for analysts or others who disagreed with him.

The top Republican and Democrat on the Senate Intelligence Committee received a limited briefing on the contents of the messages Bolton saw, but were not told the names.

"The abuse of power and the cloak of secrecy from the White House continues," Sen. Edward Kennedy, D-Mass., said of the Bolton appointment. "It's bad enough that the administration stonewalled the Senate by refusing to disclose documents highly relevant to the Bolton nomination. It's even worse for the administration to abuse the recess appointment power by making the appointment while Congress is in this five-week recess. It's a devious maneuver that evades the constitutional requirement of Senate consent and only further darkens the cloud over Mr. Bolton's credibility at the U.N."

But Republicans say the Democratic filibuster justifies use of a recess appointment.

Sen. John Cornyn, R-Texas, praised the president for using his authority "to end the obstruction against John Bolton."

"This is an important position and it's critical that it not remain vacant any longer. Bolton is exceptionally well qualified to fill this role at this time," Cornyn said in a statement. "I believe John Bolton clearly understands our hope for the U.N., and will fully dedicate himself to reforming a flawed U.N., to one that better advances the principles of democracy, freedom and respect for human rights."

Added Sen. George Allen, R-Va.: "I look forward to finally having John Bolton in place at the United Nations. The U.N. faces tremendous challenges and I believe John Bolton will bring much-needed accountability and financial responsibility to an organization in desperate need of reform after years of scandalous fraud and countenancing of repressive regimes."

Ambassador Marc Ginsburg, a FOX News foreign affairs analyst, said now that the deal is done, Bolton will get past the partisan debate because the work is too important.

"He is going to have the president's and Secretary [of State Condoleezza] Rice's imprimatur" to promote the president's agenda, Ginsburg said.

Added Weekly Standard editor Bill Kristol: "Kofi Annan has been more gracious about Bolton than the Senate minority leader or Dodd ... I hope more, some responsible Democratic senators distance themselves from these statements from Senator Dodd and Senator Reid."

Bolton fills the vacancy created by the departure of former Sen. John Danforth. Republican strategist Ed Rogers told FOX News that Bolton will have three priorities when he arrives at the international body.

"He's got to get four-square with what the U.N. is doing and isn't doing in the War on Terror," Rogers said. He will also have to make sure the international body is more engaged on Iraq. Lastly, he will have to work on "internal reform measures that the U.N. has to see through coming out of the Oil-for-Food scandal," added Rogers.

Former NATO Supreme Allied Commander, Gen. Wesley Clark, said Bolton has a tough job ahead of him.

"What he's got against him is a long record of statements people at the U.N. will be concerned about, will find offensive," said Clark, a FOX News analyst. Bolton has to both "exercise the club of U.S. financial support," as well as turn on "the charm of America."

"This is a hard thing for John Bolton to come into at this point," Clark said.

FOX News' Sharon Kehnemui Liss and The Associated Press contributed to this report.