Islamabad The United States accused Pakistan on Saturday of having links to a militant group Washington blames for an attack on the U.S. embassy and other targets in Kabul and said the government in Islamabad must cut those ties.
"The attack that took place in Kabul a few days ago, that was the work of the Haqqani network," the U.S. ambassador to Pakistan, Cameron Munter, told Radio Pakistan in comments aired on Saturday.
"There is evidence linking the Haqqani Network to the Pakistan government. This is something that must stop."
The Haqqani network is one of three, and perhaps the most feared, of the Taliban allied insurgent factions fighting U.S.-led NATO and Afghan troops in Afghanistan.
Insurgents in a bomb-laden truck occupied a building in Kabul on Tuesday, raining rockets and gunfire on the U.S. embassy and other targets in the diplomatic quarter of the Afghan capital, and battled police during a 20 hour siege.
Five Afghan police and 11 civilians were killed.
Washington has long blamed militants sheltering in Pakistan for violence in Afghanistan. Islamabad says its forces are taking high casualties fighting insurgents, and bristles at any suggestion it provides support for fighters.
Defense Secretary Leon Panetta warned Pakistan on Wednesday the United States would "do everything we can" to defend U.S. forces from Pakistan-based militants staging attacks in Afghanistan.
Munter suggested ties with Pakistan, which relies heavily on billions of dollars of U.S. aid, were still heavily strained, despite recent comments from both sides on strong counter-terrorism cooperation.
"These relations today need a lot of work," he said.
The Haqqani network is perhaps the most divisive issue between the two allies, whose ties have been badly damaged by the unilateral American raid that killed Osama bin Laden in a Pakistani town in May.
Pakistani officials were not immediately available for reaction on Munter's comments.
"The key here is that this is going to take a real effort to work together, to agree who the enemy is, to make sure that we identify those people who will attack Pakistanis, Afghans, and Americans, that we do not give them any space anywhere," Munter told Radio Pakistan.
"These people have to be pursued everywhere. We will work with our Pakistani friends to make that happen but we cannot put up with this kind of fight. We have to make sure that in our talks with your leadership, we figure out the best way to put these attacks to an end."
The United States has repeatedly pressed Pakistan to go after the network, which it believes is one of the most lethal organizations in Afghanistan and enjoys sanctuaries in North Waziristan, a global hub for militants near the Afghan border.
Pakistan's powerful Directorate of Inter-Services Intelligence (ISI) has long been suspected of maintaining ties to the Haqqani network, cultivated during the 1980s when its founder Jalaluddin Haqqani was a feared battlefield commander against the Soviet Union in Afghanistan.
Asked if the Haqqani network was behind the Kabul assault, Sirajuddin Haqqani, the group's leader, told Reuters in a telephone interview on Saturday from an undisclosed location:
"For some reasons, I would not like to claim that fighters of our group had carried out the recent attack on U.S. embassy and NATO headquarters. Our central leadership, particularly senior members of the shura, suggested I should keep quiet in future if the US and its allies suffer in future."
The Haqqanis are thought to have introduced suicide bombing to Afghanistan, and are believed to have been behind high-profile attacks there, including a raid on Kabul's top hotel and an assassination attempt on the president.
In one example of the Haqqani group's effectiveness, they are believed to have helped an al Qaeda suicide bomber who killed seven CIA agents at a U.S. base in eastern Afghanistan last year, the deadliest strike on the agency in decades.
(Writing by Michael Georgy; Editing by Diana Abdallah)