Sen. John McCainJohn Sidney McCainSenate confirms four Biden ambassadors after delay Meghan McCain to Trump: 'Thanks for the publicity' Grant Woods, longtime friend of McCain and former Arizona AG, dies at 67 MORE (R-Ariz.) on Sunday warned North Korean leader Kim Jong Un that the price of aggression is "extinction."
"In other words, make sure that Kim Jong Un knows that if he acts in an aggressive fashion, the price will be extinction," McCain said on CNN's "State of The Union."
The Senate Armed Services Committee chairman said the U.S. cannot allow Pyongyang to develop a nuclear weapons arsenal, saying he does not believe Kim is "rational."
The Republican senator also said the Trump administration should continue to work with China to convince North Korea to "put the brakes on" its missile and weapons programs.
"So far they have not," McCain said, referring to officials in Beijing.
"The third option is ... missile defense," he said, making his case for the U.S. to take steps toward developing "capabilities to defend [South] Korea."
McCain also stressed the importance of strengthening the nation's relations with its allies in the region including Japan and South Korea.
His remarks come on the same day Reuters reported that Kim celebrated his country's latest nuclear test by honoring nuclear scientists, technicians, government officials and military officers.
Following North Korea's latest nuclear test last week, the U.S. has renewed calls for additional international sanctions against the nation.
President Trump said last week that Pyongyang has been "behaving badly," while reaffirming the possibility of using military force to deal with North Korea's provocations.