Afghan decision 'very close': Obama

President Barack Obama said Wednesday his decision on more US troops for Afghanistan was "very close" and that he was just weeks away from announcing his long-awaited war strategy review.

Obama, whose administration has been warning the Afghans repeatedly that America's military commitment there will not be "open-ended," said he would be straight about the "end-game" and how long the US mission is going to take.

"We are very close to a decision. I will announce that decision certainly in the next several weeks," Obama told CNN, according to early excerpts of an interview recorded as he visited China.

The president has for weeks been mulling whether to send up to 40,000 additional US troops to Afghanistan, a decision made no easier by the political upheaval that surrounded President Hamid Karzai's disputed re-election.

"He's got some strengths, but he's got some weaknesses," Obama said of the Afghan leader, who returned to power despite widespread fraud in August presidential elections after his main challenger pulled out of a run-off.

The Obama administration has increasingly been expressing concerns about Karzai's reliability as a US ally and effective head of government, openly questioning his government's record on corruption and inability to garner popular support.

"We also have to make sure that we've got an effective partner in Afghanistan. And that's something that we are examining very closely and presenting some very clear benchmarks for the Afghan government," Obama said.

"I'm less concerned about any individual than I am with a government as a whole that is having difficulty providing basic services to its people in a way that confers legitimacy on them."

In a separate interview with NBC television, Obama said he hoped to be straight with Americans about how he had reached his decision.

"I'm confident that at the end of this process, I'm going to be able to present to the American people in very clear terms what exactly is at stake, what we intend to do, how we're going to succeed, how much it's going to cost, how long it's going to take," he said.

"I think that's what is owed the American people, because frankly, over the last several years, that's not what they've gotten."

During Obama's eight-day tour of Asia, differences emerged between key US figures on how to proceed in Afghanistan.

The top US diplomat on the ground, Kabul ambassador Karl Eikenberry -- a former commander of American forces in Afghanistan -- expressed serious doubts in a leaked cable about sending more troops before Karzai's government gets to grips with the corruption.

The ambassador's position apparently put him at odds with current Afghan war commander General Stanley McChrystal, who wants more than 40,000 extra US troops and has warned that without them the mission is likely to fail.

Asked in a third interview, this time with CBS, if such leaks were a firing offense, Obama answered, "Absolutely."

"We have deliberations in the situation room for a reason; we're making life and death decisions that affect how our troops are able to operate in a theater of war. For people to be releasing info in the course of deliberations is not appropriate."

The Afghan war faces increasingly stiff opposition from the American public, with some 800 US soldiers having lost their lives in Afghanistan and the number of casualties rising. October was the deadliest month for US forces there since 2001.