"In terms of the current operations, I would hope that it would be short, that it would be precise and avoid the loss of innocent life and that they leave as quickly as they can accomplish the mission," Gates told reporters here as he wound up a visit to Australia.

Asked how short, he said, "The shorter the better."

The three-day old offensive in northern Iraq has by the Turkish military's account killed 79 members of the Kurdish Workers Party (PKK) and drawn warnings from Iraq's foreign minister that it risked destabilising the country.

Gates, who travels next week to Ankara, said he did not think Iraq's stability was threatened by the Turkish operations, and he said Turkey has suffered from PKK attacks on Turkish troops and civilians in its territory.

But he said Turkey should show respect for Iraqi sovereignty by being more open with the Iraqi and Kurdish regional governments about its plans and intentions.

"I think there can always be improvement in the timeliness and the depth of the dialogue. I think it can't just be a one-time event. There has to be an ongoing dialogue," he said.

Gates cited the counter-insurgency lessons the United States has learned in Afghanistan and Iraq in urging Turkey to complement its military operations with initiatives aimed at addressing Kurdish grievances and eliminate popular support for the PKK.

"But these economic and political measures are really important because after a certain point people become inured to military attacks," he said.

"And if you don't blend them with these kinds of non-military initiatives then at a certain point the military efforts become less and less effective."

The US government at all levels has relayed that message to the Turkish government, he said.

Gates said that even though Turkey has had troops in northern Iraq for years, it has had to resort to air attacks and the recent ground incursion because it has not been successful in dealing with the PKK.

"So, this is a difficult long term problem, and in my view that's why it needs to be addressed in a comprehensive way," he said. "Just using the military techniques are not going to be sufficient to solve the problems."