SEOUL (Reuters) - North Korea’s state media on Friday stepped up a personal attack on former U.S. Vice President Joe Biden for slandering its leader, calling the Democratic presidential candidate “a rabid dog” that needed to be put down.

FILE PHOTO: Democratic presidential candidate former Vice President Joe Biden delivers a speech during the Women's Leadership Forum in Washington, U.S. October 17, 2019. REUTERS/Carlos Jasso/File Photo

The official KCNA news agency did not say how Biden had insulted the North’s leader, Kim Jong Un, but the 2020 presidential hopeful has been critical of U.S. President Donald Trump’s policy, saying he was coddling a murderous dictator.

Misspelling Biden’s name, KCNA said the former vice president was showing signs of “the final stage of dementia,” and the “time has come for him to depart his life.”

In a commentary, it said, “Such a guy had the temerity to dare slander the dignity of the supreme leadership of the DPRK,” using the North’s official name, the Democratic People’s Republic of Korea.

“It was the last-ditch efforts of the rabid dog expediting his death,” KCNA said. “Rabid dogs like Baiden (sic) can hurt lots of people if they are allowed to run about. They must be beaten to death with a stick, before it is too late.”

In contrast, the North has credited a “close personal relationship” between Kim and Trump for saving ties between their countries from a destructive pattern of hostility. The leaders have met three times to discuss improving ties and ending the North’s nuclear weapons program.

“It’s becoming more and more obvious that repugnant dictators, as well as those who admire and ‘love’ them, find Joe Biden threatening,” said Andrew Bates, a spokesman for Biden’s presidential campaign.

“That’s because he’d restore American leadership in the world on day one by putting our security, interests, and values at the heart of our foreign policy.”

North Korea is known for colorful attacks on foreign leaders, with propaganda posters believed to be from the country once describing Trump himself as a “mad dog.” Pyongyang also denounced Trump’s former national security adviser John Bolton as a “war maniac” and “human scum.”

Trump backed a previous personal attack on Biden by the North and dismissed criticism that he was siding with a foreign dictator over a fellow American.

In May, North Korea had called Biden “an imbecile” for criticizing its leader.