U.S. Secretary of State Hillary Clinton announced the nomination of Derek Mitchell as the first U.S. ambassador to Myanmar since 1990.
Myanmar in 2010 released Nobel Peace Prize laureate Aung San Suu Kyi from a lengthy house arrest just weeks before general elections, sparking a series of political reforms that culminated with Suu Kyi's seat in Parliament this year.
Clinton added that Washington was issuing a general license that would allow U.S. businesses to invest in the country.
Sanctions against the country, however, were suspended, not lifted, and Clinton said Washington was mindful of the abuses suffered by ethnic minorities in the country.
At least 30 people were reportedly killed in clashes in Myanmar between government troops and Kachin ethnic rebel fighters in early May.
"We will be maintaining the arms embargo, because we want to see, amongst the reforms that are taking place, a move for the armed forces to be under civilian control," she said.
Myanmar's Foreign Minister Wunna Maung Lwina said his country was appointing U Than Shwe, the country's envoy to the United Nations, as ambassador to the United States.