President Barack Obama on Monday welcomed Myanmar's president to the White House — the first such visit in nearly 50 years — and hailed the Southeast Asian nation's progress on democratic reforms, but emphasized that much work remains to be done.

After meeting privately with President Thein Sein in the Oval Office, Obama told reporters that Myanmar must release more political prisoners and take steps to end the ethnic violence that has left tens of thousands of Muslims displaced.

"This is a long journey and there is still much more to be done," Obama said. "The displacement of people, the violence directed towards them, needs to stop."