The United States has deployed Predator drones to Turkey from Iraq for surveillance flights in support of Ankara's fight against Kurdish rebels, a Pentagon spokesman said Monday.

With US forces withdrawing from Iraq by the end of the year, the four American unmanned aircraft will be shifted from an air field in northern Iraq to the Incirlik air base in Turkey, Captain John Kirby told reporters.

"There is an agreement now to fly some of those ISR (intelligence, surveillance and reconnaissance) assets out of Incirlik at the request of the Turkish government," Kirby said.

The robotic drones, which are unarmed, had been moved to Incirlik in the last couple of weeks, he said.

"It's my understanding they are operating out of Incirlik now," he said.

Violence between rebels from the Kurdistan Workers' Party (PKK) and Turkish army has escalated since the summer, with Turkey launching a major operation last month in retaliation for a PKK attack that killed 24 soldiers.

Turkey had acknowledged talks with the Pentagon on redeploying the unmanned aircraft to Incirlik.

The mission for the drones would remain the same, with only a change in the air field used by the planes, Kirby said.

"This is to help provide ISR support to the Turkish military to deal with the specific threat posed by the PKK on their southern border."

In another step designed to bolster the Turkish military in its battle with the PKK, the Pentagon announced last month plans to sell three AH-1 Super Cobra helicopters to Ankara in a deal worth $111 million.

The PKK, listed as a terrorist organization by Turkey and much of the international community, took up arms for Kurdish independence in southeastern Turkey in 1984, sparking a conflict that has claimed about 45,000 lives.