SEOUL, South Korea (AP) – North Korean leader Kim Jong Un has lobbed a string of insults at President Donald Trump, calling him a “mentally deranged U.S. dotard” and hinting at a frightening new weapon test.

The fact that it’s the first time for a North Korean leader to issue such a direct statement has raised the international nuclear standoff to a new level.

Kim says in his Friday statement that Trump will “pay dearly” for his recent threat to destroy North Korea. Kim calls Trump “a rogue and a gangster fond of playing with fire.”

Kim’s foreign minister later said North Korea may test a hydrogen bomb in the Pacific Ocean to fulfill Kim’s vow to take the “highest-level” action against the United States.