Chairman of the US Joint Chiefs of Staff, Admiral Mike Mullen has said that Pakistan's Inter-Services Intelligence (ISI) is actively supporting a network linked to al Qaeda and blamed for an assault on the US embassy in Kabul last week.Admiral Mullen accused Pakistan of exporting violent extremism to Afghanistan by allowing militants to act as an “arm” of the intelligence service.He told US senators 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 our strategic partnership, but also Pakistan's opportunity to be a respected nation with legitimate regional influence. Admiral Mullen said, by exporting violence, they have eroded their internal security and their position in the region.Rehman Malik, Pakistan's interior minister, warned the US against an imminent raid against the Haqqani leadership in North Waziristan, a mountain region close to the border with Afghanistan. He denied that the intelligence agency had ties to the network.