WASHINGTON – Defense Secretary James Mattis warned North Korea that any major threat to the U.S. or its allies would be met with a “massive military response” that would be “overwhelming” following Pyongyang’s sixth nuclear test Sunday.

“Any threats to the United States or its territories including Guam or our allies will be met with a massive military response – a response both effective and overwhelming,” Mattis said.

“Kim Jong-un should take heed the United Nations Security Council’s unified voice. All members unanimously agreed on the threat North Korea poses, and they remain unanimous in their commitment to the denuclearization of the Korean Peninsula, because we are not looking to the total annihilation of a country, namely North Korea,” he said.

“But as I said, we have many options to do so,” he said.

The comments are the first official on-camera response by the Trump administration official in response to North Korea conducting its sixth nuclear weapons test on Sunday.

The yield of the test was much higher than its last test approximately a year ago, suggesting rapid advancement in its nuclear program.

Kim claimed it was the country’s first successful hydrogen bomb test, after having said the same of its “h-bomb of justice” test in January 2016 despite experts’ skepticism. The test came after Pyongyang released photos of him allegedly reviewing a warhead small enough to fit atop an intercontinental ballistic missile that could potentially reach the U.S.

Mattis made the remarks outside of the West Wing, after a meeting with Trump and other national security advisers. He was flanked by Joint Chiefs of Staff Chairman Gen. Joseph Dunford.

Neither responded to shouted questions, including whether war with North Korea was inevitable. Asked earlier in the day whether he would attack North Korea, Trump responded, “We’ll see.”