President Donald Trump ridiculed former Vice President Joe Biden after North Korean Dictator Kim Jong-un described him as a “fool of low IQ.”

“I have confidence that Chairman Kim will keep his promise to me, & also smiled when he called Swampman Joe Biden a low IQ individual, & worse,” Trump wrote on Twitter.

Trump suggested that Kim’s mockery of Biden was a “signal” of allegiance to their relationship.

The president also dismissed North Korea’s act of firing short-range ballistic missiles, despite his National Security Advisor John Bolton decrying the tests as a violation of a United Nations resolution.

“North Korea fired off some small weapons, which disturbed some of my people, and others, but not me,” he wrote.

Trump commented on the news while in Japan, posting his remarks on Twitter at 6:30 a.m. Japanese time.