The reversal adds another Trump administration blow to decades of reconciliation efforts.

The Trump administration has told its senior diplomats in Vietnam not to take part in events marking the 50th anniversary of the end of the war.

Four U.S. officials who insisted on anonymity to describe sensitive diplomatic decision-making said that Washington had recently directed senior diplomats — including Marc Knapper, the U.S. ambassador to Vietnam — to stay away from activities tied to the anniversary on April 30.

That includes a hotel reception on April 29 with senior government leaders and an elaborate parade the next day — gatherings hosted by Vietnam in Ho Chi Minh City, also known as Saigon, where the war ended with South Vietnam’s surrender.