NATO's military commander urged countries to provide more instructors to train Afghanistan's security forces, as national representatives met Monday to pledge additional troops to join the 30,000 reinforcements committed by President Barack Obama.

Officials from NATO's 28 member nations and 15 partner countries meeting at the alliance's military headquarters in Mons, Belgium, are expected to confirm last week's pledges made by allied nations for an additional 5,000 troops.

During a meeting of foreign ministers on Friday, NATO chief Anders Fogh Rasmussen said he also expected the allies to commit "several thousand" more troops by the time of an international conference in London in January, during which the allies will discuss the war effort and an eventual exit strategy with President Hamid Karzai of Afghanistan.

The Obama administration expects its allies in the International Security Assistance Force, known as ISAF, to provide up to 10,000 additional troops. Together with the 30,000 new U.S. troops and ISAF's current 106,000 members, the international force would number over 140,000 by the middle of next year.

A "significant proportion" of the reinforcements are expected to be trainers for the expanding Afghan security forces, NATO military chief Adm. James Stavridis said Monday.

"We are really emphasizing training as the success strategy," Stavridis told reporters. "We're talking to each of the allies and asking them what training capabilities they can offer up, and we're getting a very good response on that."

A newly established allied training mission will require large numbers of instructors and mentors to enable the planned rapid expansion of the security forces.

The Afghan army has about 94,000 troops, and is slated to expand to 134,000 next year. The police force numbers about 93,000 members and is also expected to grow significantly.

Stavridis said that he expects NATO's garrison in Kosovo to be reduced in size next year from its present 10,000 troops to just "a few thousand." Some have suggested that the units freed up in the process could also be sent to Afghanistan.

"In terms of whether the troops are going to be able to go on other NATO missions, that'll be up to individual missions," Stavridis said.

Monday's meeting in Mons is part of an annual effort during which member nations commit forces for all the alliance's military missions. The national military representatives earlier committed units to NATO's naval anti-piracy and anti-terrorism patrols, and for Kosovo.

The move to significantly expand the allied and Afghan security forces comes at a time when NATO's European members are tightening defense budgets in response to the global economic downturn. Many governments also face overwhelming public opposition to the war, which many voters see as unwinnable.