The most senior American military officer and Chairman of the Joint Chiefs of Staff Admiral Mike Mullen said the militant Hakkani group is an arm of Pakistan's intelligence service. Admiral Mullen told US Senators that with the ISI support, Haqqani operatives planned and conducted the truck bomb attack as well as the assault on US embassy in Kabul. He said that Washington also have credible intelligence that Haqqani network was behind the June 28th attack against the Inter-Continental Hotel in Kabul. Mullen also said that in choosing to use violent extremism as an instrument of policy, the Government of Pakistan, and most especially the Pakistani Army and ISI, jeopardises not only the prospect of strategic partnership, but also Pakistan's opportunity to be a respected nation with legitimate regional influence. US Defense Secretary Leon Panetta also told the Senate Armed Services Committee that Washington cannot allow terrorists to have safe havens from which they launch attacks and kill US forces. He said the first order of business right now is to put as much pressure on Pakistan Earlier, a Senate committee voted to link some of Washington's future aid to Pakistan to its progress in fighting Islamist militants. Pakistan's High Commissioner in London rejected the allegations saying Pakistan has made huge sacrifices fighting terrorism in Afghanistan.