WASHINGTON - US commander General Joseph Dunford, who is leading the Nato-led forces in Afghanistan, told Congress that he has reservations about the overall effectiveness of the army operations in North Waziristan.

"They have had some success against the Pakistani Taliban and IMU [Islamic Movement of Uzbekistan] in North Waziristan from the best that we can tell, but that they certainly have not had the effect against the Haqqani Network and others that we would want to have seen. Now, although it certainly has had a disruptive effect on the Haqqani Network in essence that they have all been forced to move out of their sanctuary in the Miranshah area," he said.

He, however, stressed the need for strong relations with Pakistan as America's dependence on the crucial line of communication passing through Pakistan decreases post 2014. He said this could give the United States an opportunity to reframe relationship with Islamabad.

"I think our footprint in Afghanistan has made us reliant on the ground lines of communication. And I think after 2014 we have an opportunity to reframe our relationship with Pakistan," he told lawmakers during a confirmation hearing by the Senate Armed Services Committee.

Dunford, who has been nominated by US President Barack Obama as Commander of US Marine Corps, was responding to a question from Senator Jack Reed.

Dunford agreed with Senator John McCain that as long as the Taliban have basically a sanctuary in Pakistan, situation will remain extremely complex and dangerous. "The resiliency of the Taliban movement is driven by their sanctuary in Pakistan," he said.

Responding to questions, Dunford said the Taliban and other terrorist organisations are determined to carryout 9/11-type attacks.

"From what we see on a day-to-day-basis and from the intelligence, that there are individuals in both Afghanistan and Pakistan who are determined to attack the homeland. They are determined to replicate acts like 9/11. And the pressure that we have placed on those networks over the past decade is the reason they haven't been able to execute a 9/11," he said.

According to the American General, the Pakistani army recognises that extremism is an existential threat to the state.

"I think they are determined to do something about that threat. Less confident that they today have the capability to do all that needs to be done to deal with that threat inside of Afghanistan, which is why I think you see them focused narrowly on the most pressing threats to Pakistan, reflecting an inability to deal more broadly with extremism," he said.

"This is one of the reasons I think it's so important for us to develop an effective relationship between Afghanistan and Pakistan, and I think the United States can play a unique role in facilitating that relationship, because the way we will get after this problem is by, one, having a common definition of extremism in the region, and number two, then having an agreed-upon framework within which both Afghanistan and Pakistan can deal with the threat of extremism as well as the very real political and economic challenges that exist between the two states," he said.