Secretary of State Colin Powell thanked President Bush on Monday for bringing him into his first-term administration, but said the two had discussed it, and it's time for Powell to go.
"It has been my great honor and privilege to have been once again given the opportunity to serve my nation, and I will always treasure the four years that I've spent with President Bush and with the wonderful men and women of the Department of State," Powell told reporters Monday afternoon after the White House announced his decision to step down.
"It has always been my intention that I would serve one term. And after we had had a chance to have good and fulsome discussions on it, we came to mutual agreement that it would be appropriate for me to leave at this time," Powell said.
Bush accepted Powell's resignation, as well as those of three other Cabinet secretaries, the White House announced Monday. Education Secretary Rod Paige (search), Energy Secretary Spencer Abraham (search) and Agriculture Secretary Ann Veneman (search) are all returning to private life. White House spokesman Scott McClellan said no successors would be named on Monday.
"These are all very distinguished individuals who have served their nation with honor and distinction. They all have been valuable members of the president's team and all have played a vital role in helping the president implement his agenda," White House spokesman Scott McClellan said Monday.
"I think you saw from Secretary Powell's letter that this is a discussion that they've had for some months now -- or over recent months, at least. And Secretary Powell made a decision, for his own reasons, that this was now the time to leave," McClellan said.
Commerce Secretary Donald Evans (search) and Attorney General John Ashcroft (search) have already announced their departures. Last week, Bush nominated White House counsel Alberto Gonzales (search) to replace Ashcroft.
Bush issued written statements praising the four who announced their departures Monday, but saved the most noteworthy remarks for Powell.
"Colin Powell is one of the great public servants of our time. He is a soldier, a diplomat, a civic leader, a statesman, and a great patriot. I value his friendship. He will be missed," the statement reads.
Powell submitted his resignation letter to the president on Friday.
"As we have discussed in recent months, I believe that now that the election is over the time has come for me to step down as secretary of state and return to private life. I, therefore, resign as the 65th Secretary of State, effective at your pleasure," Powell wrote.
Powell's resignation became public during an announcement to his staff during their Monday morning meeting. He said he will stay in place until a replacement is confirmed.
"Now, I'm not leaving today. I just offered my resignation. And I expect to act fully as secretary of state until the day that I do leave. And I suspect that will be a number of weeks, or a month or two, as my replacement goes through the confirmation process," Powell told reporters.
After the announcement, lawmakers quickly issued statements lamenting Powell's departure.
“Secretary of State Colin Powell is a great leader whose military and diplomatic achievements and personal popularity have served our country well. I join countless friends of Colin Powell all over the world who have learned of his resignation with sadness," said Republican Sen. Richard Lugar, of Indiana, chairman of the Senate Foreign Relations Committee.
"He won some and he lost some, but he is a rare commodity in this town: a decent and classy guy who will be missed," said Democratic Sen. Joe Biden of Delaware, ranking member of the Senate Foreign Relations Committee.
Other foreign policy analysts also said the loss of Powell's steady determination and his popular reputation oversees will be felt by the United States.
"His loss will be a great loss not just for the administration, but for the country," Graham Allison, a former assistant secretary of defense, told FOX News.
Powell was formerly the chairman of the Joint Chiefs of Staff and managed Operation Desert Storm. He served as former President Reagan's national security adviser and was in the Army for 35 years, rising to the rank of four-star general.
Powell, who was born in Harlem, N.Y., graduated from City College of New York and earned a masters degree from George Washington University. After retiring from the military, he founded America's Promise, which provides resources to youth to help them get successful starts in life.
Allison said Powell's resignation should come as no surprise to those who have watched as the secretary tired of battles against Defense Secretary Donald Rumsfeld (search), whose national security and foreign policy views often won administration approval over Powell's more diplomatic approach.
Among those disputes was whether Al Qaeda and deposed Iraqi leader Saddam Hussein were linked. At the United Nations, Powell also staked his reputation on intelligence data that showed Hussein had weapons of mass destruction. Those weapons have not been found.
"His credibility has gone down considerably over the last couple years to the point that he and his staff have largely been engaged in, let's say, hit-and-run tactics against a more powerful secretary of defense," FOX News contributor and former ambassador Mark Ginsberg said.
"He [and Deputy Secretary of State Richard Armitage (search)] thought the White House was far too peppered with ideologues," said Chicago Tribune editor James Warren.
Observers also say that now that Palestinian leader Yasser Arafat is dead, Middle East peace negotiations are expected to be renewed with vigor, and Powell may have decided that he does not want to get started on the process and then force the administration to change horses midstream.
"Frankly, I think he's serving the president's interests. If the president wants to do something in the Middle East, it doesn't make sense for Powell to start it and then leave," said former Mideast envoy and ambassador Dennis Ross.
Ross said whoever succeeds Powell must be committed to pursuing peace in that region.
"You really have to care about the [process]. It's not only important to the United States, but you have to develop your own sense of mission and commitment to it, otherwise it's very hard to sustain it," he said.
On Powell's schedule Monday is a meeting with Israeli Foreign Minister Silvan Shalom. He is expected to keep his schedule until his successor takes over. This week, Powell leaves for Chile for the Asia-Pacific Economic Cooperation (search) Leaders Conference, then goes to Sharm 'el Sheik, Egypt, for the regional neighbors conference on Iraq.
Powell said the potential for a Middle East peace process will reveal itself in the coming weeks. He also listed several other pieces of unfinished business.
"We have to make sure that we continue to pursue the global war against terror, we have to consolidate the very significant gains we've seen in Afghanistan and we have to make sure we defeat this insurgency in Iraq," Powell said, adding that strengthening alliances and finding a solution to the Iranian nuclear program are also critical missions.
Several people have been named as a replacement, including Armitage and National Security Adviser Condoleezza Rice (search). Ginsberg said Deputy Secretary of Defense Paul Wolfowitz (search) may also want the job, but could face trouble getting confirmed because of the controversies surrounding his stewardship of the war in Iraq. Sen. Lugar is also a dark horse for the job, Ginsberg said.
Ross said that another name that could be in the running is newly-named U.S. ambassador to the United Nations John Danforth (search), a Republican and former U.S. senator from Missouri.
FOX News' James Rosen and Tony Delancey contributed to this report.