NEW YORK (Agencies) Top US officials have come to a definitive conclusion of the slaying of Tehreek-i-Taliban Pakistan chief Hakimullah Mehsud and said his death would set off a new power struggle as Al-Qaeda would find it hard to replace him with a commander of their choice. Hakimullah Mehsud was specifically chosen by Al-Qaeda to succeed Baitullah Mehsud because he was considered most allied to it. His role in facilitating the attack on the American base in Afghanistan showed how much trust Al-Qaeda had vested in him, New York Times reported quoting US officials. An Obama administration official in Washington said intelligence reports over the weekend came close to a definitive conclusion - about 90 per cent certainty - that Mehsud had died from wounds suffered in a drone strike on January 14, New York Times reported on Monday. Mehsud was believed to have been buried in a tribal plot in Pakistans tribal areas, it said. The US has been eager to retaliate against Mehsud after he claimed responsibility for the suicide bombing of a CIA base in southeast Afghanistan in late December that killed five agency officers and two private contractors, the deadliest assault against the spy agency in more than 20 years. American officials said they hoped the death of Mehsud would signal their resolve against the Taliban groups and their Al-Qaeda allies who have used Pakistans tribal areas to strike at American and Nato forces in Afghanistan. It would be a serious blow, they said, coming at a time when the group has been battered by an escalation in American drone strikes and the offensive by the Pakistani military that has disrupted their operations. The Paper quoting US intelligence officials said Al-Qaeda would find it hard to replace Mehsud with another trusted commander. But, New York Times conceded that any organisational setback could be short-lived as the two men in line to takeover from him Waliur Rehman, known as Talibans chief military strategist, and Qari Hussein, the chief trainer of suicide bombers, are considered tough operators. Qari Hussein, who trained with Lashkar-e-Jhangvi is probably favoured by Al-Qaeda over Waliur Rehman, according to the Paper. The competing versions about whether Hakimullah is alive or not centre on the aftermath of a drone attack on January 14, when he was in the village of Shaktoi, a Taliban stronghold, in South Waziristan. A member of the Pakistani Taliban, a fighter who was close to Mehsuds predecessor, said in a telephone interview on Sunday night that there were indications that Hakimullah had died. The fighter said that Mehsud had indeed been moved to Orakzai in the past week for medical treatment, and that it was possible that he had died, given the severity of his injuries and the scarcity of medical supplies.