WASHINGTON: US Senator John Kerry, a leading proponent of US aid for Pakistan, has said called for Pakistan to be more cooperative in eliminating alleged sanctuaries of Afghan militants in Pakistan.

The chairman of the Senate Foreign Relations Committee raised the issue of the continued danger of a sanctuary war being prosecuted against the forces in Afghanistan at a congressional hearing on the upcoming Nato summit in Chicago.

“I am a veteran of a sanctuary war and I know how insidious it can be, and I personally think that it is unacceptable to have a zone of immunity for acts of war against armed forces and against the collective community that is trying to accomplish what it is trying to accomplish,” the Democratic senator said in a statement.

“That means Pakistan has to become more assertive and more cooperative, and we may have to resort to other kinds of self-help depending on what they decide to do," the influential lawmaker added.

The US has been accusing Pakistan of offering assistance to militants from the so-called Haqqani network and of providing the group's leadership a sanctuary in the North Waziristan tribal region.