Stanley McChrystal, the top US general in Afghanistan, has offered to resign after he and his aides were quoted in a magazine article mocking President Barack Obama and his top advisors, CNN has reported.
McChrystal, the US and NATO commander in Afghanistan and the architect of Obama's war strategy, was summoned to Washington to explain his "enormous mistake in judgment" directly to the president, Obama's spokesman said.
Earlier, when asked whether Obama was considering ousting the general, the spokesman, Robert Gibbs, told reporters, "I would say all options are on the table."
McChrystal has apologised for the article, which quotes his aides calling one top Obama official a "clown" and another a "wounded animal."
The general himself made belittling remarks about Vice President Joe Biden and the US special envoy to Afghanistan and Pakistan, Richard Holbrooke.
McChrystal's departure would add to already growing uncertainty about the course of the nine-year-war just one year after his predecessor, General David McKiernan, was pushed out of the same job.
Gibbs said Obama became "angry" when he saw the article, due to be published in Rolling Stone magazine on Friday.
"Angry. You would know it if you saw it," Gibbs said.
Defence Secretary Robert Gates said McChrystal had "made a significant mistake and exercised poor judgment." Admiral Mike Mullen, who as chairman of the Joint Chiefs of Staff is the top US military officer, expressed his "deep disappointment."
"Gen. McChrystal has apologised to me and is similarly reaching out to others named in this article to apologise to them as well," Gates said in a statement.
Still, it was unclear whether they would accept his apology.
"It's very important for the commander in chief to have confidence in his main line troops, especially someone who's in charge of the war in Afghanistan," said Senate Majority Leader Harry Reid.
Just six months ago, Obama backed McChrystal's request for more troops, escalating an unpopular conflict in which costs and casualties are soaring.
McChrystal himself offered his "sincerest apology for this profile" before flying to Washington, where he will also meet with Gates on Wednesday.
"It was a mistake reflecting poor judgment and should never have happened," McChrystal said in a statement.
Afghan President Hamid Karzai fully backed the US general and "believes he is the best commander the United States has sent to Afghanistan over the last nine years," a spokesman said.
Defence officials say they have confidence a suitable replacement could be found for McChrystal.
Possible successors include Lieutenant-General David Rodriguez, who now serves as McChrystal's No. 2, Lieutenant-General William Caldwell, who runs NATO training mission for Afghan forces, or General James Mattis, the commander of US Joint Forces Command.
The Rolling Stone article, which quoted several McChrystal aides anonymously, portrays a split between the US military and Obama's advisers at an extremely sensitive moment for the Pentagon, which is fending off criticism of its strategy to turn around the Afghan war.
"It certainly isn't going to help relations between the White House and this building," one defence official said.
The article quotes a member of McChrystal's team making jokes about Biden, who was seen as critical of the general's efforts to escalate the conflict and who had favoured a more limited counter-terrorism approach.
"Biden?" the aide was quoted as saying. "Did you say: Bite me?"
McChrystal himself quipped: "Are you asking about Vice President Biden?". "Who's that?," he asked.
McChrystal also belittled Holbrooke. One aide said McChrystal had compared the special envoy to a "wounded animal."
"Oh, not another e-mail from Holbrooke," McChrystal groaned while checking his BlackBerry during a trip to Paris, according to the magazine. "I don't even want to open it."
McChrystal said he felt "betrayed" by the leak of a classified cable from US Ambassador to Afghanistan Karl Eikenberry last year. The cable raised doubts about sending more troops to shore up an Afghan government already lacking in credibility.
The article also quoted an adviser to McChrystal dismissing an early meeting with Obama as a "10-minute photo op."
"Obama clearly didn't know anything about him, who he was. Here's the guy who's going to run his (expletive) war, but he didn't seem very engaged," the adviser told the magazine.
"The boss was pretty disappointed."
The White House, asked about whether Obama was in fact disengaged, said McChrystal would have Obama's full attention on Wednesday.
"I think anybody that reads that article understands ... what an enormous mistake this was, given the fact that mothers and fathers all over this country are sending their children halfway across the world to participate in this," Gibbs said.
He added that parents of troops needed to know their military was "capable and mature enough."
"I think that is one of the things that the president will look to discuss tomorrow," he said.