WASHINGTON: The top US general in Afghanistan faced possible removal on Tuesday after he and his aides were quoted in a magazine article mocking President Barack Obama and his top advisers.

General Stanley 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.

Asked whether Obama was considering ousting the general, White House spokesman Robert Gibbs told reporters, “I would say all options are on the table.”

McChrystal has apologised for the article, due to be published in Rolling Stone magazine on Friday. It quotes McChrystal’s 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.

The Pentagon blasted McChrystal over his comments and stopped short of expressing confidence in his ability to continue leading the nearly nine-year-old war, seen by many analysts as in a stalemate with the Taliban.

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. But Gates offered no clue as to whether McChrystal would stay in his job.

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.

Senior US officials did not rule out that McChrystal could offer his resignation, but said it was still unclear whether Obama would accept it.

Still, other officials expressed guarded optimism that McChrystal would survive in his job because his comments — while embarrassing — did not challenge Obama’s policies. “There’s only one person who can answer that question —the commander-in-chief,” a defence official said.

An Obama administration official said McChrystal had been directed to appear in person at Wednesday’s Afghanistan meeting at the White House “to explain to the Pentagon and the commander-in-chief his quotes in the piece about his colleagues.”

US Senator John Kerry pleaded on Tuesday for a “cool and calm” reaction to scathing comments from the US commander in Afghanistan, General Stanley McChrystal, citing the urgency of the war effort.

“The top priority is our mission in Afghanistan and our ability to proceed forward competently,” Kerry said, adding that it would be up to President Barack Obama to decide whether to replace the commander.

Kerry, the Democratic chairman of the Senate Foreign Relations Committee, said he had spoken to the general by telephone and “emphasised to him that I think, obviously, those are comments that he’s going to have to deal with.”

“My impression is that all of us would be best served by backing off, staying cool and calm,” in response to the general’s sharp, personal criticisms of national security officials in Washington from Obama on down, he said.

The US ambassador to Afghanistan, Karl Eikenberry, is “fully committed” to working with General Stanley McChrystal despite scathing criticism in a magazine article, a spokeswoman said on Tuesday.

In Brussels, Nato chief Anders Fogh Rasmussen indicated support for the US commander, expressing full confidence in McChystal and his strategy, according to a spokesman.

Further turmoil emerged as Britain announced its special envoy to Afghanistan was taking “extended leave”, amid reports he clashed with military officials over strategy just a month ahead of a crucial international conference in Kabul. Britain’s Foreign Office confirmed that Sherard Cowper-Coles was on leave from his post, which also covers Pakistan.

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.

Just six months ago, Obama backed McChrystal’s request for more troops, escalating an unpopular conflict in which costs and casualties are soaring. The Rolling Stone article 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 Afghanistan war.