TOKYO — US President Donald Trump doubled down on his support for North Korean leader Kim Jong Un's scathing view of former US Vice President Joe Biden on Monday, dismissing criticism that he was siding with a dictator over a fellow American.

"Well, Kim Jong Un made a statement that Joe Biden is a low IQ individual. He probably is, based on his record. I think I agree with him on that," Trump told a news conference in Tokyo.

The comments reinforced a tweet that Trump sent on Saturday with a similar message, and drew renewed criticism of the president.

North Korea's state-run news agency issued a stinging attack last week on Biden, who has been critical of the isolated state.

Trump has targeted Biden with increasing criticism as the former vice president rises in polls for the Democratic presidential nomination to challenge Trump in 2020.

The president often derides his political opponents, but his tweet on Sunday and his comments on Monday were notable because he issued them while abroad and aligned himself with Kim, considered a brutal dictator by many.

The comments came during the US Memorial Day weekend. The federal holiday remembers and honors people who have died while serving in the US armed forces.

"We're going to have to retire the word 'unprecedented' during Trump's presidency," said Larry Sabato, presidential historian and director of the University of Virginia's Center for Politics.

"It's becoming the new normal. And disgraceful, of course," he wrote on Twitter.

One of Trump's fellow Republicans, US Representative Adam Kinzinger, called out the president on Sunday for "praising a dictator" and attacking Biden over the Memorial Day weekend.

"It's just plain wrong," Kinzinger, a military veteran, said on Twitter.

Biden's campaign and the Democratic National Committee did not immediately respond to requests for comment.

Pete Buttigieg, a Democratic candidate for president and Navy veteran, was also critical on Monday. "Kim Jong Un is a murderous dictator and Vice President Biden served this country honorably. It's just one more example, though, of the way that this president tries to draw attention to himself by saying things that shock the conscience ..."

Trump has sought to build a strong relationship with the North Korean leader in the hope that North Korea would agree to denuclearize.

Trump also knocked Biden and former President Barack Obama on Monday for their efforts to prevent Iran from getting a nuclear weapon. Trump pulled the United States out of a nuclear deal Iran sealed with Washington and other foreign powers.

"Joe Biden was a disaster, his administration with President Obama, they were basically a disaster when it came to so many things, whether it was economy, whether it was military ... no matter what it was, they had a lot of problems," Trump said, when asked about criticism that he was favoring Kim over the former vice president.

"So, I'm not a fan."

A commentary by North Korea's KCNA state media on Tuesday slammed Biden for "rhetoric slandering the supreme leadership of the DPRK (Democratic People's Republic of Korea)."

"What he uttered is just sophism of an imbecile bereft of elementary quality as a human being, let alone a politician," the North Korean news agency said. — Reuters