U.S. Defense Secretary Robert Gates (L) shakes hands with Turkey's Chief of General Staff General Yasar Buyukanit before a meeting in Ankara February 28, 2008. Turkey has given no clear timeframe for ending its military operations against Kurdish PKK rebels in northern Iraq, Gates said on Thursday after talks with Turkish officials. Gates also reiterated Washington's call for the operation, now in its seventh day, to be as short and carefully targeted as possible. REUTERS/Mark Wilson/Pool (TURKEY)