The Chairman of the Joint Chiefs of Staff, Admiral Mike Mullen, has expressed concern that Pakistan may implode with nuclear weapons in near future, and also "use" them.

"My biggest concern is that if Pakistan gets to a point where it implodes, you've got a country that could be an Islamist, theocratic country with nuclear weapons which could both use them and proliferate them. One of our goals is to make sure that doesn't happen,"The News quoted Admiral Mullen, assaying.

However, the top US military officer said he was "reasonably comfortable" as Pakistan's nuclear weapons were secure.

"The US has invested in an effort to keep the weapons secure and that Pakistan has taken significant steps in recent years, so I'm comfortable", he said.

Admiral Mullen also held Pakistan's Inter-Services Intelligence responsible for supporting elements of the insurgency inside Pakistan.

"They've got an intelligence organisation that must, in my view, change its strategic approach and be completely disconnected from the insurgents. And they're not right now," he said.