The United States is working to avoid mistakes that allowed vanquished Taliban in Afghanistan to escape into Pakistan and mastermind a deadly insurgency, the regional envoy said Thursday. "We'll continue to come back very regularly to improve coordination. That was not (the case) in 2002 and that was grievous mistake," Richard Holbrooke, US special representative for Afghanistan and Pakistan, told reporters. In the months after the 2001 US-led invasion of Afghanistan overthrew the Taliban regime in Kabul, remnants of the hardline group and Al-Qaeda allies fled into the mountains of Pakistan, where they established safe havens.