U.S. President Donald Trump defended his Democratic rival Joe Biden on Sunday, who was slammed by North Korea in an apparent response to his criticism of its leader Kim Jong Un.

In commentary Friday, North Korea’s state-run Korean Central News Agency (KCNA) called Biden, a former U.S. vice president, a “rabid dog” who should be “beaten to death with a stick.”

“Joe Biden may be Sleepy and Very Slow, but he is not a ‘rabid dog’,” Trump said on Twitter.

Read more: Trump defends Biden from scathing North Korean critique