The United States called on Pakistan on Friday to take action within "days and weeks" on dismantling Afghan militant havens and encouraging the Taliban into peace talks in order to end 10 years of war.

Crucially Secretary of State Hillary Clinton appeared to extract recognition from Pakistan that it could do more in clamping down on Afghan insurgents using Pakistani soil to attack Americans but it offered no details on how.

The top US diplomat spent Friday locked in talks with Pakistani leaders following a four-hour session late Thursday in neighbouring Afghanistan designed to quicken an end to one of America's longest wars.

Unusually accompanied by CIA director David Petraeus and the top US military officer General Martin Dempsey, she said Islamabad has a "critical role in supporting Afghanistan reconciliation and ending the conflict".

"We look to Pakistan to take strong steps to deny Afghan insurgents safe havens and to encourage the Taliban to enter negotiations in good faith," said Clinton after talks with Pakistani Foreign Minister Hina Rabbani Khar.

The United States was looking for operational action over "not months and years, but days and weeks because we have a lot of work to do to realise our shared goals," emphasized Clinton.

Relations between Pakistan and the United States deteriorated dramatically over the May 2 American special forces raid that killed Osama bin Laden near Islamabad and US accusations over the September 13 US embassy siege in Kabul.

The then top US military officer, Admiral Mike Mullen, called the militant Haqqani network a "veritable arm" of Pakistan's Inter-Services Intelligence (ISI) and accused its spies of being involved in the embassy siege.

In response, Pakistani leaders united behind calls to "give peace a chance" but Clinton said that in order to do that, "we have some work to do".

With US and Afghan troops pressing a new offensive against the Haqqani network in eastern Afghanistan, Clinton called on Pakistan to up the pressure on militant safe havens on its side of the border.

"We asked very specifically for greater cooperation from the Pakistani side to squeeze the Haqqani network and other terrorists... Trying to eliminate terrorists and safe havens on one side of the border is not going to work.

"It's like that old story: you can't keep snakes in your backyard and expect them only to bite your neighbors... Eventually those snakes are going to turn on whoever has them in the backyard."

Pakistan has so far refused to open a new offensive against the Haqqani network in its leadership base in North Waziristan, arguing that its troops are too overstretched and that the country has already sacrificed too many lives.

"It's not just military action. There is greater sharing of intelligence so we can prevent and intercept the efforts by the Haqqanis or the Taliban to try to cross the border or to plan an attack," said Clinton.

Pakistan's foreign minister, who attended four hours of talks Thursday involving military, intelligence and civilian leaders from both sides, appeared to give a commitment to do more.

"Do safe havens exist? Yes, they do exist both sides. Do we need to cooperate? Yes. We can cooperate more and achieve better results," said Khar.

It was not immediately clear how that would translate into firm action with Pakistan's powerful military considered the chief arbiter of security policy.

Pakistani policy makers have argued that military operations offer limited gains and that now is the time to concentrate on a comprehensive reconciliation ahead of the planned NATO withdrawal from Afghanistan.

Khar denied US accusations that elements within its intelligence services support Afghan insurgents.

"There is no question of any support by any Pakistani institutions to safe havens. Let me be very clear and unequivocal on that," she added.

Clinton then took her case of fighting militancy within Pakistan to what appeared to be largely Western-educated civil society leaders at a town-hall style forum.

To applause and laughter, a businesswoman likened the United States to an unsatisfied mother-in-law, but the atmosphere was less toxic than in 2009 when Clinton heard US drone attacks compared to terror.

Since siding with the US-led war on terror in 2001, Pakistan has received billions in US aid, but seen a huge surge in insecurity -- losing 3,000 soldiers in battle with the Taliban and thousands of civilians in bomb attacks.

A covert American drone war in the tribal belt, which the government has approved, has fanned anti-Americanism along with conspiracy theories propagated by mosques, the media and public figures.