WASHINGTON — Barely more than a week after boasting that he has a bigger nuclear button than Kim Jong-un, the North Korean leader, President Trump portrayed himself on Thursday as having good relations with the autocratic leader of the rogue nation.

“I probably have a very good relationship with Kim Jong-un,” Mr. Trump told The Wall Street Journal in an interview. “I have relationships with people. I think you people are surprised.”

Mr. Trump declined to say whether he had directly spoken with his North Korean counterpart. “I’m not saying I have or haven’t,” he said.

But the rosy description of his relationship with the North Korean leader was another jarring reversal in tone from a president who has spoken admiringly of Mr. Kim in some moments and mocked him in others, referring to him as a fat “Little Rocket Man.”