NUSA DUA, Indonesia (Reuters) - Myanmar vowed on Saturday to address concerns raised by US President Barack Obama, outlining far-reaching plans to make peace with ethnic rebels, gradually release all political prisoners and relax controls on freedom of expression. But its government, fearing an Arab Spring-style revolution if it moves too quickly, stressed reforms must be gradual after nearly a half century of isolation and authoritarian rule that ended when the army handed power in March to a civilian parliament stacked with former generals. No longer Southeast Asia's pariah state, Myanmar won a powerful endorsement on Friday when Obama announced Secretary of State Hillary Clinton would visit the resource-rich country neighboring China, the highest-ranking American to do so since a 1962 military coup. Obama cited "flickers of progress." That came a day after Southeast Asian leaders approved of Myanmar, also known as Burma, as chairman of its regional ASEAN bloc in 2014, paving the way for a more influential role. "We are trying our best to make an effective transition to democracy," Ko Ko Hlaing, chief political adviser to President Thein Sein, told Reuters in a wide-ranging, hour-long interview on the sidelines of the East Asia Summit in Bali, Indonesia. The fact he spoke at all is significant. Myanmar delegations studiously avoid the media at regional forums, quietly entering and leaving through auditorium backdoors. This year, officials stopped in hallways to take questions, sometimes with the flash of a smile, appearing to relish their moment. The 55-year-old former military officer once managed a team of government researchers. They studied international affairs, and watched as the world changed, first with the Internet and then as democracy took root in the Philippines and Indonesia, itself an authoritarian state until the late 1990s. Later, he became a radio and television personality before taking up his current post as the top advisor to the president., describing himself now as a "conscious reformer" who wants "dynamic but systematic and stable changes.