The State Department says the United States is making an all-out diplomatic effort to defuse the crisis spawned by cross-border attacks into Turkey by Iraq-based Kurdish PKK militants. Secretary of State Condoleezza Rice has led the effort with telephone appeals for Turkish-Iraqi cooperation on the issue. VOA's David Gollust reports from the State Department.

The Bush administration has mounted what one senior official here describes as a diplomatic full-court press to defuse a crisis over PKK attacks into Turkey that threatens a regional conflict, as well as severe harm to U.S. interests.

Secretary of State Condoleezza Rice led the effort with separate telephone appeals Sunday to Turkish Prime Minister Recep Tayyip Erdogan and to the Iraqi Kurdish regional president Massoud Barzani.

State Department Spokesman Sean McCormack says Rice urged the Turkish and Iraqi governments to work together against what he termed the common threat posed by the P.K.K., the Kurdistan Workers Party, which the United States has long listed as a terrorist organization.

He says the secretary appealed to the Turkish Prime Minister not to follow through with the Ankara government's warning of a military incursion into Iraq, a threat renewed after a PKK ambush in Turkey Sunday that killed 12 Turkish soldiers:

"We do not believe that unilateral cross border operations are the best way address this issue," he said. "The best way is to work with the Iraqi government, and we are going to do everything we can to have the Turkish and Iraqi governments working together. It is important that there be action to counter the PKK, and we need to see that action from the Iraqi government, working with the Turkish government."

McCormack did not contest an assertion by Prime Minister Erdogan that Secretary Rice had asked Turkey to put off any military action for a few days to give more time for diplomacy.

Iraqi officials contend that PKK militants are operating out of rugged areas along the Turkish border that are beyond the control of Iraqi security forces, but Turkish officials allege that mainstream Iraqi Kurdish factions have tolerated cross-border PKK operations.

Spokesman McCormack side-stepped a question as to whether the Iraqi Kurdish leaders have been doing all they can to counter the PKK. He said it is incumbent upon both the Iraqi government in Baghdad and the Kurdish regional authorities to act, and said Rice underscored this in her conversation with Kurdish leader Barzani.

U.S. Ambassador to Iraq Ryan Crocker has also been involved in the diplomatic effort, speaking to Barzani, Iraqi President Jalal Talabani, who is also Kurdish, and with Iraqi Prime Minister Nouri al-Maliki.

U.S. officials are concerned that a Turkish invasion of Iraq would upset security in the broader region, while shattering the relative peace in the Kurdish region of northern Iraq and setting back hopes for Turkish membership in the European Union.