KABUL: President Hamid Karzai on Monday left Afghanistan for talks with Barack Obama in Washington to focus on security in his war-torn country after Nato combat troops withdraw in 2014, his office said.

During his three-day official visit, a decision could be made on how many US troops will stay in Afghanistan after 2014, officials have said.

“President Karzai will hold separate meetings with President Barack Obama and other high-ranking US officials to discuss various key issues,” Karzai's office said after his departure.

Talks will focus on security, economic and political transition, equipping and strengthening Afghan forces, efforts to negotiate peace with Taliban-led insurgents and a security agreement with the United States, it said.

Karzai has expressed support for keeping US troops in Afghanistan but sensitive details -- including immunity for American soldiers and the transfer of detainees into Afghan custody -- are still under negotiation.

The US Defence Department has reportedly prepared plans to leave roughly 3,000, 6,000 or 9,000 US troops in Afghanistan.

General John Allen, commander of US and Nato forces in Afghanistan, had earlier suggested leaving 6,000 to 20,000 US troops, US media reported.

US Defence Secretary Leon Panetta has said the force would focus on preventing Al Qaeda, which was sheltered by the 1996-2001 Taliban government, from regaining a foothold in Afghanistan.

According to The Wall Street Journal, a smaller US troop presence would force the State Department to cut plans for large-scale diplomatic outposts across Afghanistan.