"We are concerned about the continuing skirmishes that are happening up there, and terrorist attacks that are being launched by the PKK (Kurdistan Workers' Party) against the Turks," said spokeswoman Dana Perino.

"We continue to urge both sides to exercise restraint -- meaning the Iraqis and the Turks -- in terms of escalating tensions between the two countries," she told reporters.

Perino emphasized that both sides "agree that the commmon problem and the common enemy is the PKK, the terrorist organization."

Asked whether Washington viewed Turkish air strikes along the Turkey-Iraq border as an escalation of the conflict, Perino replied: "I have not heard it characterized it that way."