WASHINGTON - All but a few dozen of the 16,000 U.S. Marines now in Iraq will be out by early next year, the Marine Corps commandant said Thursday, putting a solid end date on a long-anticipated exit.

Gen. James T. Conway said his Marine commanders already are moving equipment out of Anbar Province, where most of his forces have been concentrated. The larger exodus will begin shortly after the Iraqi elections.

"I see the number going down to essentially zero in, I think, sometime in spring 2010," Conway told an audience at the National Press Club. The only exception, he said, will be about 30 Marines who will be working with Iraq's fledgling Marine Corps securing oil platforms in the south around Basra.

Conway and other military leaders have said that to reinforce the Marine presence in Afghanistan, they would have to draw down in Iraq. Last month close to 11,000 Marines deployed to Afghanistan, heading to the southern Helmund province, the world's largest opium poppy-producing region.

While some of the lessons from Iraq will carry over, Conway said the Marines in Afghanistan are facing tougher terrain and cannot always wear the 80 pounds of body armour they had been wearing in Iraq.

He also said that buried roadside bombs that are triggered by pressure plates are the greatest threat the troops face in Afghanistan, although they are not quite so sophisticated as those seen in Iraq.

He said he believes the Taliban are massing for an increase in attacks. But when asked how long he believes the Marines will be in Afghanistan, Conway would say only that they will be there for as long as they are needed.

Conway also said he believes the corps can sustain between 15,000 and 18,000 Marines in Afghanistan and still give troops 14 months at home for every seven months they are deployed, a crucial rest period that also allows units to get training.

Currently 56,000 U.S. troops are in Afghanistan and 133,000 in Iraq. All U.S. combat forces are scheduled to be out of Iraqi cities by the end of this month and out of Iraq by the end of 2011.