But Washington repeated US opposition to unilateral Turkish action in neighbouring northern Iraq against bases belonging to the separatist Kurdistan Workers' Party (PKK). PKK militants are blamed for the deaths of 15 members of the security forces in southeast Turkey last week.

"Turkey, like every country, has a right and an obligation to defend itself and its people," the US said in a statement issued by its embassy in Ankara.

It followed harsh remarks on Tuesday by Prime Minister Recep Tayyip Erdogan, who said that US support for Israeli offensives against militants in Lebanon and the Gaza Strip while it opposed Turkish action in Kurdish-populated northern Iraq constituted double standards.

Like Ankara, Washington considers the PKK a "terrorist" organisation and has pledged support for Turkish efforts to combat the Kurdish separatist group.

"Terrorism is terrorism everywhere," Erdogan said. "It is not possible to agree with a mentality that tolerates country A and displays a different attitude when it comes to country B."

Earlier, US Ambassador Ross Wilson had warned that a cross-border operation against the PKK would be "unwise" and urged Ankara to coordinate its moves with the United States.

"Working together with the United States and the government of Iraq can be an essential part of advancing Turkish security," the embassy statement said.

"We look forward to continued close cooperation with Turkey ... as our countries address together the threat posed by the PKK and the other security challenges we face."

Washington argues that its forces in Iraq are overwhelmed by violence in other parts of the country and that military action against the PKK in the north could upset the relative stability of the Kurdish-populated region.

Washington's reluctance to take action against the PKK in northern Iraq, which border Turkey, has often poisoned ties with Ankara, a key Muslim ally in the Middle East.

After a series of high-level security meetings, Ankara urged Washington and Baghdad on Monday to crack down on the PKK and warned that it was ready to engage in cross-border military action if they failed to do so.

Ankara says the PKK uses mountain bases in northern Iraq as a springboard for attacks across the border in Turkey.

At least 87 PKK rebels and 51 members of the security forces have died in escalating unrest in southeast Turkey this year, according to an AFP count.

In addition, Kurdish militants claimed responsibility for 11 bomb attacks in urban centres, in which nine people were killed and nearly 140 injured.