Kabul: Afghan President Hamid Karzai on Thursday backed a proposed US strategy that would involve hitting Al Qaida and Taliban militants in neighbouring Pakistan, saying he had been calling for a changed approach for years.

"Change of strategy is essential," Karzai told a news conference. "It means that we go to those areas which are the training bases and havens of terrorists and we jointly go there and remove and destroy them."

His comments came a day after the US military conceded it was not winning the fight against the Taliban insurgency in Afghanistan and said it would revise its strategy to combat militant safe havens in Pakistan.

New strategy

US Admiral Mike Mullen, chairman of the Joint Chiefs of Staff, told the House of Representatives Armed Services Committee that he was "looking at a new, more comprehensive strategy" that would cover both sides of the Afghan-Pakistani border.

Pakistan has said it will not tolerate foreign troops entering its territory. Angered by Taliban attacks in Afghanistan, Karzai has advocated hot-pursuit missions into Pakistan before.

But while Karzai had a prickly relationship with former Pakistani army chief Pervez Musharraf, who stepped down as president last month, he has sought better ties with the new civilian president, Asif Ali Zardari.

Karzai attended Zardari's swearing-in on Tuesday, and the two leaders said they had a common goal to defeat the militants.