Ahead of Blinken's trip, the United States' top diplomat for East Asia, Daniel Kritenbrink, told reporters there had been "virtually zero progress" in efforts to get Myanmar's junta to reduce violence, free political prisoners and talk to the democratic opposition.

Southeast Asian leaders are meeting at an annual forum that will focus on the civil war in Myanmar and territorial tensions in the South China Sea, two challenges that have long tested the bloc's credibility.