An “enduring solution” in Afghanistan is the best way to make Pakistan realise how to achieve its national security aims without “allowing elements on its soil who create problems for their neighbours,” Gen David Petraeus, top US commander in Afghanistan, told lawmakers in Washington on Tuesday.

“The fact is that the Pakistanis are the first to note that more needs to be done. There is, I think, a growing recognition that you cannot allow poisonous snakes to have a nest in your backyard even if they bite the neighbour's kids, because sooner or later they're going to turn around and cause problems in your backyard,” Petraeus said, adding: “And I think that, sadly, has proven to be the case”.

Petraeus and Michele Flournoy, undersecretary for defence policy, briefed the senators about the situation in Afghanistan.

“The fact of that stability and that success will force a recalculation by a whole number of parties that will have to reckon with that and may choose to approach that reality differently and change some behaviour that we've seen in the past,” Flournoy said.

Senator Mark Udall noted that the Pakistani leadership has been “unwilling to abandon support for the Taliban because they view it as a hedge against possible future Indian influence in Kabul”.

“In the context of our new strategic partnership with India, do you think that there are new openings to engage New Delhi in a more positive political solution that might reassure Pakistan?” Udall asked the Defence Department officials.

Flournoy responded that the US had been “very heartened by the fact that India and Pakistan are resuming their own dialogue on a number of disputed issues, from Kashmir to counter terrorism, humanitarian issues, trade and so forth”.

She described such dialogue as “extremely important”, adding: “Pakistan, in particular, views? so many issues in the region through the prism of its relationship with India. And so getting at some of those root problems between the two of them is one of the most important initiatives that can happen in the region, and so we are being as supportive of that as possible.”