WASHINGTON, US (AFP) - US President Barack Obama held "candid" talks with his top military and national security advisors on Wednesday on charting progress and challenges in Afghanistan, the White House said.

The talks in the secure White House Situation Room are part of a weeks-long process the president is using to help him assess whether to send thousands more US troops into the unpopular eight-year war.

"In today's meeting, the president engaged his national security team in a candid assessment of the progress that has been made and the challenges we still face in Afghanistan and Pakistan," Obama spokesman Robert Gibbs said.

"The president has set a clear goal in Afghanistan: to disrupt, dismantle and defeat Al-Qaeda and their extremist allies," Obama said.

"When it come to decisions as important as keeping this country safe and putting our troops into harm's way, the President has made it clear that he will rigorously assess our progress.

"That is why he held this meeting today and will take the next several weeks to review our strategy."

The talks grouped administration heavy-hitters including Vice President Joe Biden, Secretary of State Hillary Clinton and Defense Secretary Robert Gates.

War commander General Stanley McChrystal, who warned in a leaked report that the conflict could be lost within a year without more troops, took part by video link-up, the White House said.

Other top military brass at the talks included chairman of the Joint Chiefs of Staff Admiral Mike Mullen and Director of National Intelligence Admiral Dennis Blair.

Obama will hold his next meeting with the top officials on October 7, Gibbs said.