Pakistan will not launch an offensive against Haqqani extremists despite Washington ramping up the pressure after a series of attacks on US targets in Afghanistan, an official said on Monday.

The US and Pakistan are key allies in the war against Islamist militants in Afghanistan, but their relationship is often troubled and hit new depths after the killing of Osama bin Laden in a covert US raid in Pakistan in May.

Pakistan's army chief of staff gathered together his top generals in an extraordinary meeting at the weekend after a series of stinging rebukes from the Americans blaming the Haqqanis and Pakistani intelligence for recent attacks.

Prime Minister Yousuf Raza Gilani is now expected to call a rare cross-party conference, although he has dismissed the American allegations as little more than finding a scapegoat for US "disarray" in the 10-year war in Afghanistan.

"I don't think the indicators are as such," a senior Pakistani security official told AFP when asked if the army was going to launch an operation in North Waziristan, near the Afghan border, where the Haqqani leadership is based.

Instead, he said, the military needs to "consolidate gains" made against local militants who pose a security threat elsewhere in Pakistan's lawless tribal belt that Washington has branded an Al-Qaeda headquarters.

Pakistan has around 140,000 troops based in its troubled northwest and says more than 3,000 soldiers have been killed since 2001 -- more than the 2,735 Western soldiers to have died fighting the Taliban in Afghanistan.

General James Mattis, commander of the US Central Command which oversees the wars in Afghanistan and Iraq, on Sunday became the most senior US commander to hold talks with Pakistani generals in Islamabad since last week's public US accusations of Pakistani involvement with the Haqqanis.

After the talks, General Khalid Shameem Wyne, chairman of Pakistan's Joint Chiefs of Staff, expressed concern about "negative statements" and said "irritants" in the US relationship come from an "extremely complex situation".

In a curt Pakistani statement, the military said it was committed to achieving "enduring peace in the region" -- something it said was only possible "through mutual trust and cooperation".

In the latest in a series of rows, Washington accused Pakistan's Inter-Services Intelligence agency of involvement in the September 13 attack on its embassy in Kabul, raising tensions to a new level.

The White House demanded Friday that Pakistan "break any link they have" with the Haqqanis, which was founded by former CIA asset Jalaluddin Haqqani and is today run by his son Sirajuddin -- based in North Waziristan.

But the Pakistani official told AFP that troops were too busy countering cross-border attacks from Afghanistan and local Pakistani militants in other parts of the tribal belt to take on the Haqqanis.

"These are kind of more pressing issues that we have to tackle. We have to consolidate the gains in Mohmand and in other tribal and northwestern regions after a series of operations in these areas," the security official said.

"As for North Waziristan, the army has at least five brigades there, which is enough to take care of the situation. There is a complete tribal structure in the region to help security forces deal with the militants and outlaws."

The outgoing top US military officer, Admiral Mike Mullen, bluntly accused Pakistan of "exporting" violent extremism to Afghanistan through proxies and warned of possible action to protect US troops.