The heads of the U.S. Olympic Committee and other sports will also testify.
"The well field is as safe as we can get the well field," Hawaii Emergency Management Administrator Thomas Travis said during a press conference.
Americans have been warned of "unusual sounds or piercing noises."
And in a stunning upset in Kentucky, a high school math teacher ousted one of the state's most powerful politicians after a wave of protests to education cuts.
"If it doesn't happen, maybe it will happen later," Trump said in Oval Office remarks alongside South Korean President Moon Jae-in.