BRUSSELS — NATO ordered its military experts Thursday to draw up plans for expanding the alliance's mission in Afghanistan - a move that could lead to Canadian troops fanning out into provincial cities and lessen the burden on the separate, U.S.-led forces fighting al-Qaida and the Taliban.

The NATO-led force of 5,500, including about 1,900 Canadians, currently operates under a UN mandate limited to the Afghan capital Kabul. NATO diplomats said the orders ask the military to prepare for a broad range of options that focus on how the alliance could help bring order to other Afghan cities and assist reconstruction efforts.

UN Secretary General Kofi Annan, Afghan President Hamid Karzai and leading aid agencies have long urged an expansion of the International Security Assistance Force in Kabul to help extend government authority into the provinces, which are often under the sway of local warlords.

NATO's military planners are due to report back Sept. 26 with an assessment of the security risks in Afghanistan and detailed plans for a wider ISAF role, diplomats said.

Any decision to expand the mission would also need approval from the UN Security Council but diplomats in Brussels said that should be a formality if NATO countries agree on the plan.

The 19-member alliance took charge of the Kabul force last month in its first military deployment mission outside Europe or North America. Alliance leaders touted the operation as a sign NATO has moved beyond its old Cold War focus and is taking on a global security role.

The Kabul force operates separately from the 11,500 mainly U.S. troops in Afghanistan fighting the remnants of the Taliban and al-Qaida under Operation Enduring Freedom.

The United States and Germany last week asked NATO to consider widening the scope of the Kabul operation to help protect mixed civilian and military teams heading out into provincial cities on reconstruction projects.

Germany, in particular, wants NATO and UN backing for its plan to send 200 troops to the northern region Kunduz to back reconstruction efforts.

Allied officials said it is too early to say how many extra troops would be involved in the plans, insisting that would become clear only after the alliance's military headquarters presents its options.

They stressed it would not mean NATO taking on the combat operations of Enduring Freedom but the presence of more allied troops helping restore order in urban areas would help ease the burden on U.S. forces stretched by the operations in Afghanistan and Iraq.

Thirty-one countries are contributing to the NATO-led force, with leading roles played by Canada and Germany.