British Prime Minister Gordon Brown said Monday that the UK will hold an inquiry into the Iraq war - but not soon. Brown backed up a pledge by his predecessor Tony Blair to call an inquiry into the conflict and its aftermath once British troops have left Iraq. In a letter to the Fabian Society, a socialist campaign group, Brown said that he recognized lessons need to be learned from how Britain and the United States planned for the war and its aftermath. "There will come a time when it is appropriate to hold an inquiry," Brown was quoted as writing in the letter, according to the Independent newspaper. But Brown told the campaign group that no inquiry could be held while Britain is focused on aiding Iraqis to establish security and prosperity.