The United States has indications that elements of Pakistan's ISI military intelligence agency provide support to Taliban or Al Qaeda militants, senior US military officers said on Friday.

Navy Admiral Mike Mullen, chairman of the US Joint Chiefs of Staff, and Army General David Petraeus, head of US Central Command, said the agency must end such activities.

The officers made their remarks as the United States unveiled a new strategy for Afghanistan and Pakistan, which promises more aid for Pakistan but seeks increased co-operation in the fight against Al Qaeda and Taliban militants in return.

Mullen noted Pakistan's ISI service had links to militants on both its western border with Afghanistan and its eastern border with India.

"Fundamentally, the strategic approach with the ISI must change and their support for militants, actually on both borders, has to fundamentally shift," he told CNN television's "Situation Room" program.

Asked if there were still elements within the ISI who sympathized with or supported Al Qaeda and the Taliban, Mullen said: "There are certainly indications that that's the case."

Although links between the ISI and Islamist militants are widely suspected, it is rare for senior US officials to talk publicly about them, for fear of damaging possible co-operation with Pakistani authorities.

The New York Times, citing anonymous US officials, reported on Wednesday that the Taliban's widening campaign in southern Afghanistan was made possible in part by direct support from ISI operatives.

A senior US intelligence official, asked on Friday to describe the problem of ISI information-sharing with militants, said, "too big, too often."

He said Pakistan had in the past failed to act on "actionable intelligence" that could lead to a strike against militants.

US funding

Petraeus, speaking on PBS television's Newshour program, noted some militant groups had been established by the ISI, with US funding, with the aim of helping drive Soviet forces out of Afghanistan in the 1980s.

"Those links were very strong and some of them, I think, unquestionably do remain, to this day. It is much more difficult to tell at what level those links are still established," he said.

Petraeus said there were some cases "in the fairly recent past" in which the ISI appeared to have warned militants that their location had been discovered.

"It's a topic that is of enormous importance, because if there are links and if those continue and if it undermines the (anti-militant) operations, obviously that would be very damaging to the kind of trust that we need to build," he said.

Petraeus' headquarters is responsible for U.S. military operations in a volatile swath of the world which stretches from the Middle East into Central and South Asia.

The intelligence official said the United States and Pakistan viewed militant groups differently, and that Pakistan focused on those it saw as the biggest threats to itself, which meant it overlooked some groups with a higher US priority.

"Our intelligence shows that these groups also threaten them, so we are asking them to be a little bit more enlightened, to rethink their security calculus in a way that we think is consistent with ours," he said.-Reuters