WASHINGTON- The U.S. cannot envision success in Afghanistan without cooperation from Pakistan, a top American commander based in Kabul has told lawmakers. "I find it difficult to envision success in the region without cooperation of Pakistan and without an effective relationship between Afghanistan and Pakistan," General Joseph Dunford, Commander of U.S. and NATO forces in Afghanistan, told lawmakers during a Congressional hearing. "Over the past year I've been encouraged on a couple of fronts. One is Ibelieve that Pakistan also recognizes the existential threat of extremism to their own security, and they also recognize that it's not in their best interest to have anything other than a stable, secure and unified Afghanistan," he said. Mr. Dunford said, since August the heads of state have met four times, which is very positive. "That hasn't happened in quite some time. With Pakistan’s Prime Minister Nawaz Sharif has come new resolve to improve the relationship between Afghanistan and Pakistan," he said. "The two areas that they have identified for cooperation I think are important to point out. One is to have a common definition of extremism and to cooperate on dealing with extremism. And the other is to come up with a broader border management framework that would address the political issues, the economic issues as well as the security issues between the two countries," Mr. Dunford said. "Our role is to work on developing a constructive military-to-military relationship between Afghanistan and Pakistan," he said. Referring to his meeting with the Pakistan Army Chief, Mr. Dunford said that he has indicated a strong resolve to improve the relationship between the Afghan security forces and the Pakistani army as have his Afghan counterparts. "We will spend a lot of time over the next several months doing that. One of the things we want to accomplish by the end of the year is to have a constructive bilateral relationship between Afghanistan and Pakistan," he said. "Heretofore over the last few years, it's actually been trilateral. We've played an important facilitating role and we hope over time to work ourselves out of that role, certainly maintain effective bilateral relationships with both countries, between the U.S. and Pakistan and U.S. and Afghanistan, but play less of a role in the important relationship between those two countries," Mr. Dunford said. The United States is very carefully watching the peace talks between the Pakistani government and the Tehreek-e-Taliban Pakistan (TTP), General Joseph Dunford has told lawmakers. "We're watching that very carefully. To be honest, we don't have any insight into exactly the status of those - of those discussions. What we have seen recently is continued violence by the TTP - the Pakistani Taliban," Dunford said. "We've also seen some limited military operations, particularly in the North Waziristan area against the TTP," Mr. Dunford said in response to a question. "But what we know is what you know, and that is that Pakistan’s Prime Minister Nawaz Sharif and the leadership in Pakistan are committed to try to find some peaceful resolution and that's certainly in Pakistan as well as in Afghanistan - what needs to happen in the long term," he said. "It's just not clear to me today if the conditions are set for constructive peace talks between the TTP -- the Pakistani Taliban - and the government of Pakistan. But it's clear that they're working to that end," Dunford said.