LONDON/KABUL (Agencies) - British Prime Minister Gordon Brown and Afghan President Hamid Karzai have endorsed new US strategy to target militants safe havens in Pakistan's border areas. Brown said he'll discuss a new approach to policing the Afghan-Pakistan border in talks with US President George W Bush. Brown said the two leaders were holding a video conference on Thursday to assess the work of US and NATO troops in Afghanistan. Brown says a new strategy is needed to halt the flow of Taliban and militant fighters between Pakistan and its neighbour. He told reporters that he'll soon meet in London with Pakistan's new President Asif Ali Zardari to discuss authorisation for cross-border raids. In Kabul, President Hamid Karzai endorsed Thursday a new US focus on the Afghan and Pakistan border in its "war on terror," saying it was something his government had been pushing for years. US Joint Chiefs Chairman Admiral Michael Mullen said Wednesday he had commissioned "a new, more comprehensive military strategy for the region that covers both sides of that border" between Afghanistan and Pakistan. The United States says the area is a safe haven for insurgents, including those attacking international troops fighting a Taliban-led insurgency in Afghanistan. "The change in strategy or a new strategy is something I and my colleagues in the Afghan government had suggested three, three-and-a-half years ago," Karzai told reporters. "Our words have been clear in this regard: a change in strategy is needed, meaning that we must go to places where there is training and hide-out facilities (for terrorists) and jointly we must go there and destroy that." Karzai and his government have long said that war-weary Afghanistan should not be the sole battleground for the "war on terror" launched in response to the September 11, 2001 attack on the United States. They have called for more focus on what they say are the "roots" of the insurgency - extremist sanctuaries and training grounds in Pakistan which are sending fighters across the border to Afghanistan.