KABUL (AFP) - Pakistan must attack insurgents in its northern areas and tackle extremists threatening its stability and complicating international efforts in Afghanistan, a senior US diplomat said Thursday. The United States is committed to helping Pakistan fight insurgents, deputy assistant secretary for South and Central Asian Affairs Patrick Moon told reporters in Kabul. Hours earlier suspected US spy drones fired missiles into a school set up by a Taliban commander in a Pakistan tribal area, killing 11 people, in the latest in a string of attacks that have raised tensions between the countries. "Pakistan needs to and is attacking insurgents in its northern areas," Moon told reporters during a visit to Afghanistan to assess efforts to fight a growing Taliban-led insurgency. "Sanctuaries for Afghanistan Taliban in Pakistan complicate our security operations in Afghanistan. Pakistani Taliban elements and other extremists such as Al-Qaeda are posing a threat to the stability of Pakistan ," he said. Moon said the United States was committed to helping Islamabad by improving its army and providing development aid to stimulate economic activity and create jobs as an alternative to insurgent activity. He said relations between Afghanistan and Pakistan appeared to have improved with the September election of President Asif Ali Zardari, but "much more needs to be done."