The United States has asked South Korea to redeploy to Afghanistan the troops it has just withdrawn from Iraq, a report said Tuesday.

The US made the "unofficial" request when the "Zaytun" contingent withdrew from the northern Iraqi city of Arbil this month after a four-year deployment, Dong-A Ilbo newspaper quoted Seoul military sources as saying.

A defence ministry spokesman said no official request has been received.

He said the Seoul government would consider assistance to Afghanistan after assessing the political situation there and domestic factors.

South Korea sent non-combat forces to both Afghanistan and Iraq to support its closest ally the United States.

It pulled its 210 medical and engineering troops out of Afghanistan in 2007 after 23 South Korean Christian aid workers were taken hostage by Taliban rebels.

Seoul said the timing of the withdrawal was unrelated to the abductions. Two hostages were murdered before the remainder were freed.

South Korea sent 3,600 engineering and medical troops to Iraq in 2004, the third largest foreign troop presence at the time.

It extended the deployment four times at the request of the United States but gradually cut the numbers until the final soldiers returned home last Friday.

The troops provided medical services to almost 89,000 local residents around Arbil and offered vocational classes to more than 2,000 people. They also built a variety of clinics and other public buildings.

"The US seems to want the Zaytun unit to set another successful example of civil-military operations in Afghanistan, since it brought security and stability to Arbil over the past four years," a military source tol Dong-A.

The United States has pledged to send up to 30,000 extra troops to Afghanistan by mid-2009 to defeat a growing Taliban insurgency.