"I don't really -- I don't know that for a fact," Panetta told in an interview to CNN when asked about the links between the ISI and the Haqqani network as was alleged by Mullen in his testimony before a Congressional Committee last month. Pakistan had denied such a link.
"What I do know is that, as we have made clear, the Haqqanis have a safe haven in Pakistan, and you can't have a safe haven. These are individuals who cross over into Afghanistan and kill Americans. These are terrorists. And then they return back to Pakistan to that safe haven," he said.
"We have urged the Pakistanis to take action to make sure that that safe haven does not exist. That's the message we have given to them," the defence secretary said.
"Now, the Pakistanis, I realise, they have tried to maintain some relationships with some of these individuals. I realise that they are concerned about how they protect their own country," he said.
"But we have got to build the cooperative relationship with them. What we have got to do is build a trusting relationship where we both understand that our major effort has to be to end terrorism, period," Panetta said.
The defence secretary argued that the US can't afford to cut off its relationship with Pakistan.
"We can't afford to do that. It's been a complicated relationship with Pakistan. The reality is that terrorism is a much a threat to Pakistan as it is to the US," he said.
"As a matter of fact, they have lost thousands of people because of terror attacks in places like Karachi and elsewhere. And they understand the threat of terrorism, but they also can't pick and choose among terrorists. If you're against terrorism, you got to be against all terrorism. And that's where we have some differences," Panetta said.