WASHINGTON — President Obama on Friday lifted sanctions against Myanmar, declaring that the government there had made “substantial progress in improving human rights,” even though the country’s army is in the midst of a brutal campaign to drive out the Rohingya, a Muslim minority.

The announcement, which came on a Friday afternoon in a blandly titled email, was the final step in Mr. Obama’s efforts to transform the relationship with a once reclusive government.

The sanctions that were lifted applied to United States government aid to the government of Myanmar. Restrictions imposed by Congress, including sanctions related to North Korea and those governing arms sales and military cooperation, will remain in place.

In September, Mr. Obama pledged to lift sanctions during a visit by Daw Aung San Suu Kyi, the country’s leader, whose victory last year was viewed by the Obama administration as a triumph of the president’s strategy of engaging with countries the United States had long shunned.