NATO will not take part in a proposed US strategy of conducting raids into Pakistan from Afghanistan against Taliban and Al-Qaeda militants, a spokesman said on Thursday, reported a private TV channel. "The NATO policy, that is our mandate, ends at the border," James Appathurai told a regular news briefing in Brussels. "There are no ground or air incursions by NATO forces into Pakistani territory." Appathurai said he was sure the issue would be discussed when 26 NATO defence ministers debate Afghan strategy at a September 18-19 meeting in London. But he added: "Let me stress, it is not NATO that will be sending its forces across the border." The spokesman said a solution needed to be found to growing extremism in tribal areas of Pakistan bordering Afghanistan. "Pakistan needs to take effective action in cooperation with the rest of the international community and the Afghans to address the problem that is increasingly threatening Pakistan's stability as well as Afghanistan's," he said. On Wednesday, the US military conceded to Congress that it was not winning the fight against the Taliban insurgency and said it would revise its strategy to target militant safe havens in Pakistan. US Admiral Mike Mullen, Chairman of the Joint Chiefs of Staff, told the House of Representatives Armed Services Committee he was "looking at a new, more comprehensive strategy" that would cover both sides of the Afghan-Pakistani border. Helicopter-borne US commandos carried out a ground assault last week in Pakistan's South Waziristan tribal region, the first known incursion into Pakistan by US troops since the 2001 invasion of Afghanistan. It killed 20 people.