"We understand the Government of Burma (Myanmar) has ordered today the release of over 93 prisoners, including about 50 political prisoners," said State Department spokesman Patrick Ventrell at a briefing.
"So we welcome and encourage the unconditional release of all prisoners, but we do note that they have released about 50 today," he told reporters.
The released prisoners, pardoned a week after the fall of Myanmar's new year, included three foreigners and prisoners of conscience, according to media reports from the Southeast Asian nation.
The order by Myanmar's President U Thein Sein said that the move was made in view of ensuring stability and lasting peace of the state, national reconciliation, inclusiveness in political process and turning the prisoners to ones who take their fair shares in state building.
In November 2012, 518 prisoners including 31 foreigners were released in Myanmar under the previous two amnesty orders by U Thein Sein.
A total of 29,668 prisoners have been pardoned since Myanmar's new civilian government took office on March 30, 2011.
At the Tuesday briefing, Ventrell said that in response to Myanmar's moves, Washington has eased economic sanctions on the country, including authorizing the export of U.S. financial services and allowing for new U.S. investment in Myanmar.
"But we have a calibrated policy that includes sanctions authorities and leaves them in place as a means to encourage continued progress on reforms," he added.