Thein Sein arrived Monday in the United States for a two-day visit to meet with U.S. President Barack Obama. Myanmar's government has received international recognition for democratic initiatives that began with general elections in 2010.
Human Rights Watch said many of Myanmar's security challenges remained sidelined, however. Asia director John Sifton said 2012 was a "devastating" year for the minority population in Myanmar, known also as Burma.
"President Obama should insist on steps to prevent further outbreaks of violence. He must also make it clear that there are consequences if the Burmese government fails to implement its previous human rights pledges," he said in a statement.
The organization said several security pledges made by Myanmar's government in recent months have faltered. There are around 120,000 people displaced by various conflicts in Myanmar and more than 140,000 minority Muslims are housed in closed camps for displaced people.
"There are negative consequences for rights when diplomatic rewards continue even as reforms stall," Sifton said.
The International Crisis Group was criticized this year for rewarding Thein Sein for political reforms.