PHNOM PENH, Cambodia – On a history-making trip, President Barack Obama on Monday paid the first visit by an American leader to Myanmar and Cambodia, two Asian countries with troubled histories, one on the mend and the other still a cause of concern.

Cheered by massive flag-waving crowds, Obama offered long-isolated Myanmar a “hand of friendship” as it rapidly embraces democratic reforms. Hours later, he arrived in Cambodia to little fanfare, then pointedly criticized the country’s strongman leader on the issue of human rights during a tense meeting.

Obama was an early champion of Myanmar’s sudden transformation to civilian rule after a half-century of military dictatorship. He’s rewarded the country, also known as Burma, with eased economic penalties, increased U.S. investment and now a presidential visit, in part to show other nations the benefits of pursuing similar reforms.