US President George W. Bush urged British Prime Minister Gordon Brown on Sunday not to set timetable for the withdrawal of troops from Iraq. Bush issued his call ahead of a visit to Britain, the final stop of a European farewell tour on which he has won support for ratcheting up of pressure on Iran over its nuclear programme. He said in an interview with Britain's newspaper that the United States and Britain, Washington's main ally on Iraq, both obviously wanted to bring their troops home but this could only be "based upon success". Only about 4,000 British troops are still in Iraq, most of them stationed at a base in the south. Bush has a more formal relationship with the British leader than with Brown's predecessor Tony Blair, Washington's staunchest supporter over Iraq.