"We hope that this is just a short-term incursion so that they can help deal with the threat" of Kurdish separatists, spokeswoman Dana Perino told reporters.

The Turkish army meanwhile said it had killed 41 fleeing fighters in its strike against the Kurdistan Workers' Party (PKK), which for decades has waged a bloody struggle in southeastern Turkey for an independent Kurdish homeland.

"We understand that ... Turkey wants to protect their citizens," Perino said, but reiterated President George W. Bush's calls for Turkey to show restraint.

"We are in communication and dialogue with them to make sure that this is handled in a way that is narrow, narrowly targeted, to hit the PKK and to limit and hopefully cause no civilian casualties," she said.

Bush's administration has said that Turkey coordinated with US forces in Iraq when launching its crackdown on the PKK. Iraq's government urged Turkey to pull out as soon as possible, saying the incursion threatens its sovereignty.

Washington, Ankara and other powers classify the PKK as a terrorist organization. The conflict in Turkey has claimed more than 37,000 lives since the PKK took up arms in 1984.

According to Turkish army figures, the current offensive has claimed the lives of 153 rebels and 17 Turkish soldiers since Thursday.

"It's obviously not an ideal situation. The ideal situation would be that the PKK no longer exist in Iraq," Perino said.

"The PKK is a common enemy of Turkey and the United States; and Iraq, in its fragile state of an emerging democracy, is concerned about what's happening on its northern border."