There is a growing willingness among U.S. military leaders to pull marines out of Iraq and send a substantial number to Afghanistan, a top marine commander said Monday.

Defence Secretary Robert Gates "would not object to the idea of a fairly strategic shift of focus of marines from Iraq to Afghanistan," Gen. James Conway, the Marine Corps commandant told the Associated Press in an interview.

More than a year ago, when early discussions of sending more marines to Afghanistan became public, Gates signalled opposition to the idea, preferring to maintain the concentration on Iraq.

At that time, Conway said that Gates and other military leaders believed the timing wasn't right to shift marines out of the western Iraqi province of Anbar.

Military officials now realize that the marines are an expeditionary fighting force that is better suited to the Afghanistan battle than serving Iraq, he said Monday.

Several marine units will be moving into Iraq in January and February, and it is too late to redirect them to Afghanistan, Conway said. Instead, another large turnover of units in Anbar around April could be shifted to Afghanistan if they are notified soon, he said.

Conway has made no secret of his belief that marines could be put to better use fighting in Afghanistan than their current peacekeeping mission in Iraq.

Peacekeeping and nation-building — roles that troops are playing to a larger degree in Iraq now — are "not our forte," Conway said.

Marine units tentatively scheduled to go to Iraq next spring are already incorporating some training for Afghanistan into their preparations, he said.

Taliban strengthening hold on Afghanistan: think tank

In an illustration of the growing U.S. military challenge, an international think tank said in a report released Monday that the Taliban has a "permanent presence" in nearly 72 per cent of Afghanistan, up from 54 per cent a year ago.

The report, published by the International Council on Security and Development, described the Taliban as "the de facto governing power" in some towns and villages in southern Afghanistan.

It said the militant group has managed to advance into Afghanistan's western and northwestern provinces, as well as some areas north of Kabul, the capital.

Gen. David McKiernan, the commander of U.S. and NATO troops in Afghanistan, has said he needs up to 20,000 additional troops, including four combat brigades and thousands of support troops.

Other military leaders have cautioned, however, that they first need to build the infrastructure to accommodate the troops, including housing and helicopter pads.

Conway countered that the marines could move in far more quickly because they don't need to wait for such logistical improvements.

Marine units generally enter combat with whatever resources they need, including their own combat aviation units and helicopters that would enable them to move through the mountainous terrain.

Gates has not yet approved additional forces for Afghanistan, but it's expected he may do that fairly soon. After that, military leaders will decide which units will go.

Asked about the expected cut in U.S. forces in Iraq, Conway acknowledged there's a running joke in the military that his marines want to leave Iraq because there's not enough action there.

The marines, should they arrive next year, would join about about 2,500 Canadian soldiers, most of whom are stationed in the southern province of Kandahar. The number of Canadian soldiers to die in Afghanistan since 2002 was pushed to 100 on Friday, when Cpl. Mark McLaren, Pte. Demetrios Diplaros and Warrant Officer Robert Wilson were killed in a roadside bomb blast.