The release of the prisoners, including a Nobel laureate and two opposition leaders, was part of a monthslong rapprochement between Washington and Minsk.
Sviatlana Tsikhanouskaya, a Belarusian opposition leader, welcoming Ales Bialiatski, a political activist released by Belarus, as he arrived Saturday at the U.S. Embassy in Vilnius, Lithuania.
The chair of the National Transportation Safety Board warned that a provision in the new defense bill would worsen the risk of midair collisions near the Washington-area airport where a deadly crash in January killed 67 people.