June 23, 2010 -- President Obama today relieved embattled Gen. Stanley McChrystal from his position as the top U.S. commander in Afghanistan for his remarks belittling administration officials, replacing him with Gen. David Petraeus, currently head of United States Central Command.

McChrystal's conduct, as detailed in the Rolling Stone article, "does not meet the standard that should be set by a commanding general," the president said today. "It undermines the civilian control of the military that is at the core of our Democratic system, and it erodes the trust that's necessary for our team to work together to achieve our objectives in Afghanistan."

The president praised McChrystal for his "extraordinary dedication" and "love of the country," but made it clear the comments McChrystal and his aides made could jeopardize the U.S. mission in Afghanistan.

"All Americans should be grateful for Gen. McChrystal's remarkable career in uniform. But war is bigger than any one man or woman, whether a private, general or a president, " the president said. "I believe that it is the right decision for our national security."

Obama said the change was needed to maintain unity of U.S. efforts in Afghanistan and to "hold ourselves accountable to standards that are at the core of our democracy." The president reaffirmed that the change in personnel didn't mean a change in U.S. policy.

"I welcome debate among my team, but I won't tolerate division," he said.

The embattled general, who was named the top commander in Afghanistan a year ago, met Obama for about 30 minutes this morning. He offered his resignation and the president accepted it, and no formal letter of resignation was offered, an administration official said.

In a written statement, McChrystal said he resigned out of "a desire to see the mission succeed."

"This morning the president accepted my resignation as Commander of U.S. and NATO Coalition Forces in Afghanistan," McChrystal said. "I strongly support the president's strategy in Afghanistan and am deeply committed to our coalition forces, our partner nations, and the Afghan people. It was out of respect for this commitment -- and a desire to see the mission succeed -- that I tendered my resignation."

Obama spoke with Defense Secretary Robert Gates earlier today about possible replacements, including Petraeus, who was thought to be the best choice, since he would provide "the greatest amount of continuity" with the mission.

On the ground, news of McChrystal's dismissal and Petraeus' new position was met with surprise, but also a sense of relief that an experienced commander will take the helm.

As one Marine told ABC News, "the softball is teed up for Petraeus to hit it out of the park."

Some Marines said the new position may be a bit of a comedown for Petraeus, 57, who is best known for turning around the Iraq war in 2007 and is widely credited with devising the U.S. counterinsurgency strategy. In September 2008, as Petraeus was leaving Iraq, Gates dubbed him the "hero of the hour."

In Washington, lawmakers also heaved a sigh of relief at Petraeus' pick, well regarded on both sides of the political aisle for his leadership in the Iraq war.

"This is the most pressing theater, the most pressing mission, and Petraeus is someone who has the relationships and has the relationship with the president, and has the experience dealing publicly with people and the press," said Nate Fick, chief executive of the Center for a New American Security. "It's a good save."

Petraeus' pick won in Republican circles and muted any criticism that could have emerged from McChrystal's removal.

"There is no one more qualified or more outstanding a leader than Gen. Petraeus to achieve successful conclusion of the Afghan conflict," Sen. John McCain, R-Ariz., ranking member of the Senate Armed Services Committee, said today.

House Minority Leader John Boehner, R-Ohio, called Petraeus "the right person to take over this command."

In a statement, Sen. John Kerry, D-Mass., who chairs the Senate Foreign Relations Committee was similarly enthusiastic.

Obama's "decision to return General Petraeus to the battlefield provides not just continuity in philosophy, but tested diplomatic skill that is at the very center of a military strategy which hinges on progress in governance to sustain military gains," Kerry said.

But Republicans did take the opportunity to question the administration's timetable for withdrawal.

"David Petraeus is our best hope," Sen. Lindsey Graham, R-S.C., said. "If things don't change, nobody can pull out of Afghanistan."

Petraeus' confirmation on Capitol Hill is expected to be swift, but it is likely to refocus attention on the war in Afghanistan, at a time when the White House agenda is grappling with a multitude of domestic issues, including the oil spill in the Gulf of Mexico and the economy.

The war in Afghanistan has become the longest war in U.S. history, and more than 1,000 troops have died there since the U.S. invaded the country in 2001.

Comments made by McChrystal and his aides to freelance writer Michael Hastings highlighted the lack of trust between the military and civilian leaders, and raised widespread concern over whether that would jeopardize U.S. operations in Afghanistan.

But despite the anger in the White House over McChrystal's comments, the government of Afghan President Hamid Karzai threw its full support behind McChrystal and warned that his departure could disrupt U.S.-Afghanistan partnership. McChrystal was often the intermediary between Karzai and U.S. leaders such as ambassador Karl Eikenberry, whose distrust of Karzai is well documented.

NATO Secretary General Anders Fogh Rasmussen said in a statement that the group will continue to support the U.S. strategy and carry on as normal despite McChrystal's departure.

"Our operations in Afghanistan are continuing today, and they will not miss a beat," he said.

British Lt. Gen. Parker will serve as the temporary NATO commander until Petraeus is confirmed, the British government announced today.

McChrystal Steps Down: 'A Sad, Tragic Day'

President Obama was "stern" today as he proceeded through a series of meetings that resulted in McChrystal's ouster, a senior White House official said this afternoon.

The message from the president today was that everyone involved in the mission "needs to remember why we're doing this," the official said. "He doesn't want to see pettiness. This job isn't about personalities and reputations, it's about the men and women in uniform and serving our country."

It undermines the mission and the unity of the team implementing the policy -- including U.S. allies, such as the French, who were also disparaged by McChrystal and his team in the Rolling Stone story, the official added.

"This was a sad, tragic day," the official said.

McChrystal had informed Gates on Tuesday that he was prepared to resign, but contrary to reports Tuesday from other news outlets, he didn't offer his resignation until today, the official said.

After McChrystal left the White House, the president met for roughly 45 minutes with Gates, Vice President Biden, Chairman of the Joint Chiefs of Staff Admiral Mike Mullen, White House chief of staff Rahm Emanuel, and National Security Adviser Gen. James Jones to discuss next steps.

Immediately after that meeting, the president met with Petraeus and offered him the job.

"Petraeus had a sense that his name was being discussed," the official said.

The president also spoke to his Cabinet, key lawmakers and and Karzai to inform them of the decision.

McChrystal admitted during his round of phone calls to top Obama administration officials that he had "compromised the mission," a senior administration source told ABC News earlier today.

On Tuesday, Obama said McChrystal and his team showed "poor judgment," but that he wanted to meet with him face to face before making a decision on whether to fire him.

Officials feared that McChrystal's influence would be diminished and could jeopardize the momentum of the U.S. counterinsurgency strategy in Afghanistan. At the same time, officials realized how closely tied McChrystal was with the current counterinsurgency strategy, and the fact that Gen. David McKiernan was dismissed from the same job last summer could cause upheaval in operations on the ground.

'The Runaway General'

The profile published in Rolling Stone, titled "The Runaway General," characterized McChrystal as an outsider who did not relate well with the administration, and as a military leader who was "disappointed" with his first meeting with the president.

Hastings said McChrystal was fully aware of the notebook and tape recorder that the freelance journalist always had in his interviews.

"It was a sort of natural kind of recklessness that General McCrystal had, that has been with him through his entire career, as I understand it, I hear from the special forces community," Hastings told ABC News' Diane Sawyer Tuesday. "Their willingness to take a risk is a part of their whole persona. And inviting me in, was a obviously a risk, as it always is when you invite a journalist in."

McChrystal and his aides criticized several top U.S. officials, including U.S. special envoy to Pakistan and Afghanistan Richard Holbrooke -- dubbed a "wounded animal." McChyrstal also said he felt betrayed by Eikenberry for the ambassador's criticism of Karzai in a leaked cable.

One of the article's most disparaging remarks comes from an unnamed adviser to McChrystal, who described the general's first meeting with Obama.

"Obama clearly didn't know anything about him, who he was," the aide said. "Here's the guy who's going to run his [expletive] war, but he didn't seem very engaged. The boss was pretty disappointed."

McChrystal himself spoke openly about the time the president criticized him for speaking too bluntly about needing more troops last fall.

"I found that time painful," McChrystal said in the article. "I was selling an unsellable position."

After news of the comments stunned the political and military circles from D.C. to Afghanistan, McChrystal quickly issued an apology for his "bad judgment."

"I extend my sincerest apology for this profile. It was a mistake reflecting poor judgment and should never have happened," McChrystal said in a statement. "Throughout my career, I have lived by the principles of personal honor and professional integrity. What is reflected in this article falls far short of that standard."

In his apology, McChrystal said he had "enormous respect and admiration for President Obama and his national security team, and for the civilian leaders and troops fighting this war" and said he remains "committed to ensuring its successful outcome."

Duncan Boothby, a civilian press official in Afghanistan, resigned in the aftermath of the scandal.

Biden -- who one McChrystal adviser referred to as "Bite Me" -- was one of the few officials named in the story who did not comment, except to say Tuesdasy that he will have "plenty of time to talk about Afghanistan."

ABC News' Z. Byron Wolf and Jonathan Karl contributed to this report.