WASHINGTON: Al-Qaeda is trying to “bring down” nuclear-armed Pakistan, US Vice President Joe Biden warned Sunday, days after a war review tip-toed around Islamabad's role in fighting extremists.

“Our overarching goal and our rationale for being there is to dismantle, ultimately defeat Al-Qaeda... to make sure that terrorists do not, in fact, bring down the Pakistani government, which is a nuclear power,” Biden said.

The vice-president, in an interview with NBC's “Meet the Press” program, repeated threads of a one-year report on the US military surge in Afghanistan that pointed to progress but warned that more time was needed.

Unveiling the policy assessment on Thursday, President Barack Obama urged Islamabad to do more to rein in extremists holed up along the Afghan border but also renewed US commitment to major aid programs for Pakistan.

The report trod carefully on the uneasy US anti-terror ally following pointed criticisms of Islamabad's nuclear safety and other areas of policy revealed in the US cables published by WikiLeaks and other reports.

Many experts say Pakistan is far less willing to take action against militants seen as useful in fighting rival India or in preserving Islamabad's influence in Afghanistan.

While the war review called relations with Pakistan “substantial” a departure from private US assessments that question Islamabad's commitment to fighting extremists, it did urge some readjustment.

“For instance, the denial of extremist safe havens will require greater cooperation with Pakistan along the border with Afghanistan,” it said.

Biden measured success against Al-Qaeda by noting it had been restricted to efforts like the botched underwear attack on a US-bound jetliner last Christmas and a failed amateurish bombing in New York's Times Square in May.

“They are planning much smaller bore but yet deadly attempts to go after the United States of America. We saw that in the underpants bomber last Christmas. We saw that in the Times Square effort.

“We have significantly degraded and knocked off a lot of the main planners and organizers and trainers. Does that mean we've succeeded? No. Does that mean we're in much better shape than we were a year ago and two and three? Yes.”

Obama on Thursday said Afghan progress was sufficient to permit a “responsible reduction” of US forces to begin in July 2011, though the size of the likely drawdown appeared limited.

The assessment comes one year after the president announced both a surge of 30,000 extra troops to Afghanistan and the conditions-based July troop drawdown.