The U.S. military insisted on Sunday it would be out of Iraqi cities by the end of June and indicated that President Barack Obama would announce "shortly" if troops would be redeployed to Afghanistan.
Obama last week approved an extra 17,000 soldiers for Afghanistan, having been asked for near twice that number, confirming that Washington's focus was shifting from Baghdad to Kabul as the security situation in Iraq improves.
"There is no doubt that we will be out of the cities by June," US military spokesman Major General David Perkins told reporters in Baghdad, reiterating a commitment made to the Iraqi government under a deal struck last November.
Under the so-called Status of Forces Agreement, all US troops must leave Iraq by the end of 2011, and troop numbers are already being reduced.
There are 146,000 US soldiers in Iraq and only 38,000 in Afghanistan, according to the latest Pentagon figures.
Perkins said detailed discussions were "ongoing" between General Ray Odierno, the top US commander in Iraq, and Washington, on whether troops would be moved to Afghanistan.
"We have just finished a fairly large reduction and we are in the process of readjusting our forces on the ground," Perkins said.
"General Odierno is in discussions with the secretary of state and secretary of defence about what he thinks is needed here. I would imagine shortly that the president will make a decision and we will go through with it."
Obama has launched a comprehensive policy review of US strategy in Afghanistan and neighbouring Pakistan due before the April 3-4 NATO summit in Strasbourg, France and Khel, Germany.
The US president has said that more troops are needed in Afghanistan, which he regards as the frontline in the battle against Al-Qaeda, as the situation there is deteriorating.
The approval of 17,000 troops last week followed a request from the US commander in Afghanistan, General David McKiernan, for 30,000 more soldiers.
Under the orders, 8,000 marines from the 2nd Marine Expeditionary Brigade will deploy to Afghanistan in late spring, and about 4,000 soldiers from the 5th Stryker Brigade, 2nd Infantry Division will deploy in mid-summer, the Pentagon has said. Some 5,000 support troops will arrive later.
Obama indicated that the units had initially been earmarked for Iraq, but said the drawdown of US forces there "allows us the flexibility to increase our presence in Afghanistan."
NATO officials have warned that security in Afghanistan is likely to be a bigger problem in the coming months in the run-up to presidential elections scheduled for August.
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