The two leaders also discussed US Secretary of State Condoleezza Rice's upcoming trip to the Middle East and "ways to address the humanitarian needs of the Lebanese people" amid Israeli strikes, said spokeswoman Dana Perino.

"They also discussed the continuing PKK terrorist attacks against Turkey. The president told the prime minister that the United States will work with Turkey to deal with this terrorist threat," said Perino.

The two leaders had also spoken on the telephone Thursday, after Ankara threatened a cross-border operation if Washington and Baghdad fail to crack down on the separatist Kurdistan Workers' Party (PKK) in northern Iraq.

The warning followed a series of security meetings in Ankara after the killing last week of 15 security force members by PKK militants.

"I told him (Bush) we want to cooperate with the Iraqi government and he said he agrees we should work together on this issue," Erdogan told reporters late Thursday during a visit to northern Cyprus, the Anatolia news agency reported.

"But I also told him that the limits of our tolerance have been seriously breached and we cannot just put aside the fact that we had 15 martyrs in three days," Erdogan said.

Like Ankara, Washington considers the PKK a terror organization and has pledged support to its NATO ally Turkey in combating the group.

But it has been reluctant to crack down on the PKK in northern Iraq, arguing that allied forces are overwhelmed by violence in other parts of the country and that military action in the north could destabilize the relatively calm Kurdish-populated region.

Washington has warned Turkey against unilateral cross-border action, drawing angry accusations from Erdogan that it is using double standards in the region -- a reference to US support for Israeli offensives against Islamist militants in Lebanon and the Gaza Strip.