With questions being raised on the credibility of the Pakistan government's probe into the killing of former Prime Minister Benazir Bhutto, US has offered to provide "any assistance or guidance" required by Islamabad for a "full investigation" into the assassination.The Bush administration, however, made it clear that Pakistan has not asked it for any help."Obviously, they're a sovereign government and they will have to be conducting that investigation. We have offered to provide any guidance or assistance that is requested," White House deputy press secretary Scott Stanzel said at a briefing in Crawford, Texas."At this time, as far as I'm aware, none has been requested of the United States, but that is a matter for the Pakistani government to move forward on; it's early in the investigation," he said.The spokesman said that it was in the interest of the people of Pakistan that a "full investigation" is held."I think it's in the interest of long-term prospects for democracy in Pakistan that that be the case," he said."And we stand ready to help Pakistan, should they request our assistance with that.... I think that 's what everyone expects and I think that's in everyone's interests," Stanzel added.The White House also insisted that the Pakistan government should set a specific date for election in case the vote is put off. (Reporting by Sridhar Krishnaswami)COMPLETE COVERAGE: TURMOIL IN PAKISTAN