A Turkish Super Cobra attack helicopter heads to the border as it flies past snow-covered mountains after taking off from a military base near the southeastern Turkish town of Cukurca, bordering Iraq, February 28, 2008. The United States called on Thursday for NATO ally Turkey to end its major ground offensive against Kurdish PKK rebels in northern Iraq as soon as possible, but Ankara said it would stay until the job was done. REUTERS/Stringer (TURKEY)

An undated handout picture provided by the Turkish Chief of General Staff army headquarters on February 28, 2008, shows Turkish soldiers during an operation against Kurdish guerrillas in northern Iraq. U.S. President George W. Bush said on Thursday Turkish troops should withdraw from Northern Iraq "as quickly as possible." "The Turks need to move, move quickly, achieve their objective and get out," he told a White House news conference. REUTERS/Turkish Chief of Staff/Handout (IRAQ). FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS..

In this photo released by the Turkish General Staff headquarters on Thursday, Feb. 28, 2008, a Turkish soldier uses binoculars to search the area during an operation against Kurdish rebels at an undisclosed location. Turkey on Thursday declined to set a timetable for the withdrawal of Turkish troops fighting Kurdish rebels in Iraq, despite calls from the United States to quickly wrap up the operation. Also on Thursday, Turkey's military said its troops killed seven more rebels in the fighting in Iraq, bringing the total claimed death toll to 237 rebels since Turkey's ground incursion began a week ago. (AP Photo/Turkish General Staff, HO)

A Turkish soldier takes part in an operation in northern Iraq in this undated handout picture provided by the Turkish Chief of General Staff army headquarters and released to Reuters February 24, 2008. REUTERS/Turkish Chief of Staff/Handout

Turkish tanks move near the southeastern Turkish town of Silopi, near the Iraqi border, February 21, 2008. The Turkish military shelled several Kurdish rebel positions inside northern Iraq on Thursday, an Iraqi security official said. Turkey has massed tens of thousands of troops along its frontier with Iraq. It has carried out several small-scale cross-border commando operations and aerial bombing raids against rebels of the outlawed Kurdistan Workers Party (PKK). REUTERS/Stringer (TURKEY)

A Turkish soldier stands guard next to an armoured vehicle at the village of Sheladiz near the Iraqi-Turkish borders February 27, 2008. Picture taken February 27, 2008. REUTERS/Ceerwan Aziz (IRAQ)

Turkish armoured vehicles are seen outside a military base in the village of Bamerni near the Iraqi-Turkish borders February 27, 2008. Picture taken February 27, 2008. REUTERS/Ceerwan Aziz (IRAQ)

Turkish military helicopters and vehicles are seen in Cukurca in Hakkari province, on the Turkey-Iraq border, Thursday, Feb. 28, 2008. Turkey declined Thursday to set a timetable for the withdrawal of its troops fighting Kurdish rebels in Iraq, despite calls from the United States to quickly wrap up the operation. (AP Photo/Burhan Ozbilici)

Turkish army helicopter returns from a combat mission in northern Iraq to its base in Cukurca in Hakkari province on the Turkey-Iraq border, Wednesday, Feb. 27, 2008. Turkish troops have killed 77 Kurdish rebels in the most intense fighting of a week-old ground incursion in northern Iraq, the military said Wednesday. (AP Photo/Burhan Ozbilici)