Washington: The US military`s top officer bluntly accused Pakistan of "exporting" violent extremism to Afghanistan through proxies and warned of possible action to protect American troops.
In a scathing and unprecedented condemnation of Pakistan, Admiral Mike Mullen on Thursday said the country`s main intelligence agency ISI was actively supporting Haqqani network militants blamed for an assault on the US embassy in Kabul last week.
"The Haqqani Network, for one, acts as a veritable arm of Pakistan’s Inter-Services Intelligence agency," Mullen told the US Senate Armed Services Committee.
Pakistan`s Interior Minister rejected the US accusations of Islamabad`s links to the Haqqanis.
The minister, Rehman Malik, also warned against a unilateral US ground attack on the Haqqanis, who are based in Pakistan`s ungoverned tribal territories.
"The Pakistan nation will not allow the boots on our ground, never. Our government is already cooperating with the US ... but they also must respect our sovereignty," Malik said in an interview.
A CIA asset turned al Qaeda ally, the Haqqani network is probably the most dangerous faction in the Afghan Taliban. In the 1980s, the United States funnelled arms and cash to the Haqqani faction to counter Soviet forces.
Mullen said Haqqani militants -- with ISI backing -- this month carried out a truck bombing on a NATO base in Afghanistan that wounded 77 Americans; assaulted the US embassy and NATO headquarters in the Afghan capital; and in June staged an attack on the InterContinental hotel in Kabul.
The admiral`s tough language follows a series of stern warnings from top US officials on Pakistan`s inaction over the Haqqani network, raising the possibility of unilateral US action.
"If they keep killing our troops that would not be something we would just sit idly by and watch," Mullen said of the Haqqani insurgents.
The Central Intelligence Agency already carries out drone bombing raids on al Qaeda and other militants in Pakistan`s northwest tribal areas, strikes which US officials do not explicitly acknowledge.
The US warnings carry particular weight in the aftermath of the American raid that killed al Qaeda chief Osama bin Laden on May 02 in Abbottabad, north of the capital Islamabad, an operation that angered and embarrassed Pakistani leaders.
US officials chose not to notify Pakistan in advance of the nighttime operation by Navy SEAL commandos, fearing that officials might tip off bin Laden`s inner circle.
Defence Secretary Leon Panetta, appearing at the same Senate hearing, expressed frustration over Haqqani sanctuaries in Pakistan and renewed a vow that the United States would safeguard its troops.
Panetta, who presided over the bin Laden raid as CIA chief, declined to say what steps the government might take -- amid speculation the US might expand drone strikes to a wider area or even stage an operation similar to the bin Laden raid.
But he said the United States had made clear that it would do whatever is necessary to protect American troops.
As Pakistan and the United States appeared headed on a collision course, Islamabad this week promised action against the Haqqanis if Washington provided sufficient intelligence. But officials denied the al Qaeda-linked Taliban faction operated on Pakistani soil.
Mullen, who in the past has tended to employ more diplomatic language on Pakistan, told senators the country was jeopardising its partnership with Washington as well as its regional influence by "choosing to use violent extremism as an instrument of policy”.
He added: "By exporting violence, they have eroded their internal security and their position in the region."
While Pakistan has maintained ties to some militants as a hedge to counter its arch-foe India, the gamble has proved a failure, he said.
To defuse underlying tensions in South Asia, Panetta said both India and Pakistan need to work to reach a peace settlement over the disputed region of Kashmir.
"It`s tough politically in both areas, but in the end, we are never going to achieve stability in that region until the issues between Pakistan and India are resolved," he said.
In his last appearance before the Senate committee as he prepares to step down this month as chairman of the US Joint Chiefs of Staff, Mullen defended his efforts to build a dialogue with Pakistan`s military.
Despite mixed results, Mullen said he had helped keep the lines of communication open in more than a two dozen meetings with his Pakistani counterpart, Army Chief General Ashfaq Kayani.
In the wake of the bin Laden raid, the United States has agreed to cut by about half its military presence in Pakistan, from 300 troops to no more than 150, while virtually eliminating a role for special forces training Pakistani units, officials said this week.