STOCKHOLM - US President Barack Obama will announce in the next few weeks how many combat troops the United States will leave in Afghanistan in 2014, US Secretary of State John Kerry said on Tuesday.

Obama has set next year as the target for withrawing most troops but the decision is a delicate one as sufficent forces must stay behind to train and support Afghan forces and carry out some operations.

"Very shortly, not too long from now, the president does intend to make public what his plans are for post-2014," Kerry told reporters.

Kerry declined to discuss how many troops might remain but said: "He (Obama) is committed to supporting the Afghan military beyond 2014."

US lawmakers have been pressing military commanders and the Obama administration to release recommendations for the size of a force to remain in Afghanistan.

US troops first went into Afghanistan after the September 11, 2001, attacks on the United States to root out al Qaeda and its Taliban protectors.

Kerry said Afghanistan was beginning its first "fighting season" with its own forces holding most responsibility for military operations and they were doing well.

General James Mattis, who leads the US military's Central Command, said in March he has recommended keeping 13,600 US troops in Afghanistan after 2013.