Hillary Rodham Clinton, the US secretary of state, has announced that Washington will exchange ambassadors with Myanmar in response to its freeing of political prisoners and other reforms.<br /><br />Clinton announced the move on Friday after state media announced that Thein Sein, Myanmar's president, had issued a pardon and freed 651 detainees, including some of the country's most famous political inmates.<br /><br />Rosiland Jordan reports from Washington DC.