By Joyce Lee and Ginger Gibson

The criticism contrasts with North Korea’s repeated references to the good relationship between Kim and U.S. President Donald Trump. Kim said in April that his personal relationship with Trump was still good despite the collapse of their second summit in Vietnam in February.

Biden’s campaign responded to North Korea by calling the relationship between Trump and Pyongyang “antithetical to who we are.”

Biden, at a campaign launch in Philadelphia on Saturday, said: “Are we a nation that embraces dictators and tyrants like (Russian President Vladimir) Putin and Kim Jong Un?”

Korean Central News Agency (KCNA), the state media, responded to Biden’s criticism in a commentary late on Tuesday.

“What he uttered is just sophism of an imbecile bereft of elementary quality as a human being, let alone a politician,” it said.

Biden campaign spokesman Andrew Bates, in a statement responding to the KCNA remarks, repeated that Kim is a dictator and a tyrant.

“Trump has also been repeatedly tricked into making major concessions to the murderous regime in Pyongyang while getting nothing in return,” Bates said. “Given Vice President Biden’s record of standing up for American values and interests, it’s no surprise that North Korea would prefer that Donald Trump remain in the White House.”

KCNA listed previous controversies concerning Biden, including allegations of plagiarism and falling asleep during a speech by President Barack Obama in 2011.

“We will never pardon anyone who dare provoke the supreme leadership of the DPRK but will certainly make them pay for it,” KCNA said, using North Korea’s official name, the Democratic People’s Republic of Korea.

Denuclearisation talks have stalled since the breakdown of the second meeting between Trump and Kim in February, and North Korea conducted more weapons tests this month. The tests were seen as a protest by Kim after Trump rejected his calls for sanctions relief at the Hanoi summit. (Reporting by Joyce Lee in Seoul and Ginger Gibson in Washington Editing by Paul Tait and Leslie Adler) DM