The United States announced Wednesday that it would begin to ease a longstanding ban on imports from Myanmar, one of the last major economic sanctions on the country, because of the advances made by its military-led government in moving toward a more democratic system.

The announcement was made by Secretary of State Hillary Rodham Clinton during a meeting in New York with U Thein Sein, a former general who is now president of Myanmar. He has been directing the gradual transition away from the two decades of dictatorship and isolation that had driven the country to near economic collapse and dysfunction.

“We have watched as you and your government have continued the steady process of reform,” Mrs. Clinton, who has been ensconced in meetings with world leaders gathered for the United Nations General Assembly, told Mr. Thein Sein at the Mark Hotel in Manhattan. “And we have been pleased to respond to specific steps that recognize the government’s efforts and encourage other reforms.”

Mr. Thein Sein, who was making his first visit to the United States to attend the General Assembly, responded: “The people of Myanmar are very pleased with the easing of economic sanctions by the United States. We are very grateful for the actions of the United States.” He presented Mrs. Clinton with a large envelope containing a letter to President Obama.