The United States has renewed its economic sanctions against Myanmar and urged the military-backed regime to go much further after it reduced prisoners' terms by just one year. In a formal notice to Congress on Monday, President Barack Obama said that he was renewing sanctions that would otherwise have expired this month. The Obama administration in 2009 launched an engagement drive with Myanmar, concluding that the previous Western policy of trying to isolate the regime had failed.Myanmar's President Thein Sein, in a message read on state television yesterday, said that the government was reducing all prisoners' sentences by one year and commuting the death penalty to life imprisonment. The regime last year released Nobel Prize-winning opposition leader Aung San Suu Kyi, who has spent most of the last two decades under house arrest. But human rights groups say more than 2,000 other political prisoners remain.