LONDON: US and Pakistani authorities disagree sharply over claims that senior Al-Qaeda leader Ilyas Kashmiri was killed in a recent missile strike, officials from both countries said on Monday, suggesting sharp strains persist between authorities in Washington and Islamabad. Two days ago, intelligence officials in Pakistan claimed that Kashmiri, a figure in both Al-Qaeda and a Pakistan-based affiliate, was killed by a US drone-borne missile in northwestern Pakistan. Pakistani officials subsequently issued a series of statements about Kashmiri's death. The nation's interior minister told reporters on Monday: “I can confirm 100 percent that he is dead. I got this information this morning.” But US officials familiar with counterterrorism activities in the region said they still were unable to confirm Kashmiri's death. It was more likely than not, they said Monday evening, that the militant leader was still alive. “It wouldn't be the first time that reports of his death have been wrong,” one US official told Reuters. “We're simply unable at this time to confirm reports of Kashmiri's demise. Our working assumption is that he's still walking around.” A second US official said government experts believed it was more likely that Kashmiri was alive, though they are not ruling out the possibility he was killed in a drone strike. The conflicting assessments from Washington and Islamabad indicate relations between the US and Pakistan, which hit a low point after the US killing of Osama bin Laden last month in Pakistan, remain deeply troubled despite claims by both countries that they were improving. Kashmiri was wrongly reported to have been killed in a September 2009 drone strike. It is difficult to confirm the identities of people killed in drone strikes because they occur in remote areas not accessible to foreign journalists.