President Barack Obama said on Tuesday that the United States' principal goal in Afghanistan remains to "root out" al-Qaeda and its extremist allies, and that he would make a decision on whether or not to send more troops to Afghanistan in "the coming weeks."

US President Barack Obama (R) meets with Spain's Prime Minister Jose Luis Rodriguez Zapatero in the Oval Office of the White House, in Washington D.C. Oct 13, 2009. [Xinhua]

"We are going through a very deliberate process ... That's what we're doing not just on the military side, but also on the civilian side," said the president after meeting with Spanish Prime Minister Jose Luis Rodriguez Zapatero in the White House.

"Our principal goal remains to root out al-Qaida and its extremist allies," said Obama, adding that the United States is concerned about the stability not only in Afghanistan, but also in Pakistan.

"The military security that's provided and our ability to train Afghan forces is one element of it. Another element of it is making sure that we are doing a good job in helping build capacity on the civilian side," he said.

"I would expect that we will have a completion of this current process in the coming weeks," said the president, whose administration has been reviewing an overall strategy of the war in Afghanistan.

General Stanley McChrystal, the top US commander in Afghanistan, warned that the United States would lose the war against al-Qaeda and Taliban without rapidly sending up to 40,000 additional troops to Afghanistan.

By the end of this year, according to previous deployment plans, there will be a total of 68,000 US troops in Afghanistan.

Some administration policymakers, including Obama himself and Vice President Joe Biden, claim that they must review the overall strategy of the war in Afghanistan before sending more troops.