Turkey has charged that the separatist Kurdistan Workers Party (PKK) based in northern Iraq and linked to a two-decade-old insurgency in eastern and southeastern Turkey is acting under the protection of Iraqi Kurds who are allied to the United States.

Violence increased in recent months as rebels hiding in the rugged mountains of northern Iraq slipped back across the border to attack Turkish troops, effectively ending a unilateral ceasefire the PKK declared in October 2006.

The PKK subject was part of talks in Washington Monday between Rice and Iraqi foreign minister Hoshyar Zebari.

"We discussed the importance of not allowing Iraqi territory to be used for acts of terrorism against neighbors in this case, particularly against Turkey," Rice told reporters after the talks.

She underlined the importance of a trilateral security mechanism that Iraq, the United States and Turkey had set up some time ago and "the importance of accelerating" its work "because the Iraqis do not want and we do not want their territory to be used for terrorist acts against their neighbor."

The PKK, regarded as a terrorist group by the United States and much of the international community, has fought for Kurdish self-rule in southeast Turkey since 1984 in a conflict that has claimed more than 37,000 lives.

Turkey has repeatedly demanded tougher action from Iraq and the United States against the Kurdistan Workers Party (PKK), and refuses to rule out acting unilaterally if its demands are not heeded.

Zebari, noting a Turkish defense buildup along the border with Iraq, warned Sunday that any military incursion by Ankara into the Kurdish north of Iraq would undermine Iraq's sole haven of stability and was in no one's interest.

Zebari, himself a Kurd, said Baghdad was in consultation with the Turkish government to ease tensions.