WASHINGTON — Large numbers of US troops are no longer needed on the ground in northern Iraq to defuse Arab-Kurdish tensions and have begun handing over control to local forces, a US commander said Thursday.

Army Major General David Perkins, who leads 5,000 US troops deployed in northern Iraq, said the American contingent has gradually withdrawn from checkpoints that it had overseen to prevent clashes between Kurdish troops and Iraqi army and police.

"So we no longer have US forces on any of those checkpoints permanently as we did before," Perkins told reporters via video link from Iraq.

"And that has gone exceptionally well" with no incidents reported since the beginning of September, he said.

Three US battalions used to work at the checkpoints in the north but after an 18-month transition, the Iraqi forces were in charge, Perkins said.

"Clearly there is not the need for them (US troops) to play the role they had, especially in the numbers they had. We have proven right now that out at the checkpoints they can run perfectly fine without US presence there at all."

His upbeat comments reinforced suggestions from the former commander in Iraq, General Ray Odierno, who said recently that progress in transferring security duties to local forces could mean a large contingent of American troops would not be required to contain tensions.

The US troop presence in northern Iraq is a pivotal issue in Washington and Baghdad as the two countries negotiate a possible future US military mission in Iraq beyond an end-of-year deadline.

The remaining 46,000 troops in Iraq are due to pull out of Iraq by the end of 2011 unless the two governments strike a deal.

US commanders and some lawmakers have previously argued that keeping a brigade in northern Iraq was crucial to preventing ethnic war there by allowing the Americans to play a peacekeeping role.

But if the Pentagon decides 4,000-5,000 troops are not required in the north, that would allow US officials to agree to a smaller overall troop footprint after 2011 and possibly make the deal easier to sell politically for Iraq's government.

US officials say the administration is weighing a proposal to keep only about 3,000-4,000 troops in Iraq after 2011 in a mission focused mainly on training, with private contractors taking over some tasks previously performed by the military.

Perkins said he expected the US still to play a mediating role in the north but "at the very senior level" without large numbers of troops deployed.

He acknowledged underlying tensions between the Kurds and Iraqis over boundaries and oil resources but said any spark for potential violence would come from political discord and not from friction between the Kurdish and Iraqi government troops and police on the ground.

The 4th Infantry Division soldiers in the north have drawn down to 5,000 from 10,000 and will withdraw from Iraq completely by the end of October, leaving behind a small number of American troops, the general said.