Sen. John McCain, R-Ariz., a member of the Senate Foreign Relations Committee, called North Korean leader Kim Jong Un “this crazy fat kid” in an interview Wednesday on MSNBC.

“He’s not rational,” McCain said. “We not dealing even with someone like Joseph Stalin, who had a certain rationality to his barbarity.”

Read: North Korea Tests Possible Intercontinental Ballistic Missile

Kim has been testing the Trump administration, conducting multiple missile tests and apparently ramping up for a sixth nuclear test. He also is suspected of ordering the assassination of his half-brother, Kim Jong Nam, at Kuala Lumpur airport in Malaysia earlier this year.

Secretary of State Rex Tillerson, who visited Asia last week, said everything is on the table when it comes to dealing with North Korea, including a pre-emptive strike if the threat posed by the Hermit Kingdom becomes more serious.

North Korea has shrugged off threats of new sanctions and has thumbed its nose at the U.S., producing a video for its state-run YouTube channel, posted four days ago, showing its forces blowing up a U.S. aircraft carrier and a fighter jet.

“China is the one, the only one, that can control Kim Jong Un, this crazy fat kid that’s running North Korea,” McCain said. “They’re the ones. They could stop North Korea’s economy in a week.”

Read: North Korea Blaming South Korea For Killing Of Kim Jong Un's Half-Brother

North Korea’s latest missile test, conducted Wednesday, failed, the rocket exploding within seconds of launch, the U.S. Pacific Command and the South Korean Defense Ministry said. South Korea said it is expecting more missiles to be fired in coming weeks as the North winds up winter training drills, Yonhap News Agency reported.

Choe Myong Nam, deputy ambassador at the North Korean mission to the United Nations in Geneva, told Reuters Tuesday the country plans to accelerate its nuclear and missile programs despite the threats of new sanctions, including plans to develop “first-strike capability” and an intercontinental ballistic missile.

Sen. John McCain describes North Korean leader Kim Jong Un as "this crazy fat kid." Above, Kim visits a construction site in Pyongyang, March 16, 2017. KCNA/Reuters

As the North continues to build up its weaponry, a U.N. report released Wednesday indicated 40 percent of North Koreans are undernourished and more than 70 percent are dependent on government food handouts. The report by the World Food Program also says most North Koreans lack basic health care and sanitation. The report estimates 18 million of the country’s 24.9 million people are in need.