By David Morgan

WASHINGTON, Aug 27 (Reuters) - The top U.S. Marine officer on Wednesday said he could reduce his 25,000-strong force in the former al Qaeda stronghold of Iraq's Anbar province to reinforce military operations against a growing Taliban threat in Afghanistan.

Marine Corps Commandant Gen. James Conway told reporters the once-restive province west of Baghdad could be turned over to Iraqi security control within days, thanks to the sharp decline in violence after Sunni tribal leaders switched allegiance from al Qaeda to the U.S. military.

"The requirement right now in Iraq is much more about nation-building than it is fighting. And quite frankly, young Marines join our corps to go fight for their country," he said at a Pentagon briefing.

"It's our view that if there's a stiffer fight going on someplace else ... then that's where we need to be."

U.S. and NATO forces in Afghanistan face an intensifying insurgency marked by escalating attacks and military casualty rates that have helped make Afghanistan a deadlier place than Iraq for U.S. troops in recent months.

The United States has 33,000 troops in Afghanistan, including 3,400 Marines who are due to leave the country by the end of November.

Two Marine regimental combat teams deployed in Iraq are part of a U.S. force of about 146,000 and were sent to Anbar at the height of a Sunni insurgency that used Anbar province as one of its main strongholds.

'LESSER NUMBERS'

Conway said the size of any Marine force deployed to Afghanistan ultimately would be smaller than the one now on duty in Iraq.

"A battalion of Marines in Afghanistan count for more than a battalion of Marines in Iraq," he said. "We can do with a lesser number of Marines in Afghanistan, I believe at this point, and have the same effect."

U.S. defense officials have long recognized the need to redeploy troops from Iraq to Afghanistan but no final decision has been made about redirecting forces.

Defense Secretary Robert Gates and other top Pentagon officials are considering ways to increase the number of U.S. combat brigades in Afghanistan to confront the Taliban.

So far, the Pentagon has taken only small steps by ordering one-month tour extensions for Marines and deploying less than 200 additional support troops.

Conway suggested a drawdown of Marines in Iraq could allow for the replacement of about 1,200 troops from the 2nd Battalion, 7th Marine Regiment that are in the country until Nov. 30 to train Afghan security forces.

But he said it was unlikely that fresh Marines forces would be deployed to replace the 2,200 Marines fighting Taliban insurgents in southern Afghanistan.

"We think there is a way to backfill with some Marines if there's a commensurate decision to draw down in Iraq and we think the conditions are such there that that's plausible," Conway said.

"We cannot replace them without having to draw down elsewhere," he added. "And the only 'elsewhere' at this point that I see available is in Iraq."

The Marine commandant said strains on the corps posed by deployments to Iraq and Afghanistan could be eliminated by reducing the number of Marines on duty worldwide to 15,000.

There are about 34,000 Marines deployed worldwide including the 25,000 in Iraq and 3,400 in Afghanistan, the Marine Corps said. (Editing by Xavier Briand)

AlertNet news is provided by