Defense Secretary James Mattis offered a dark outlook of what war with North Korea would look like hours before the rogue regime launched another ballistic missile.

Mattis said in a televised interview with CBS News’ “Face the Nation” on Sunday that a conflict with North Korea would be “probably the worst kind of fighting in most people’s lifetime.”

“The bottom line is it would be a catastrophic war if this turns into a combat if we’re not able to resolve this situation through diplomatic means,” he said.

Later Sunday, North Korea tested a short-range Scud ballistic missile off of its eastern coast, the U.S. military said. The statement said the missile flew for six minutes until it landed in the Sea of Japan.

South Korea's Joint Chiefs of Staff said the missile flew about 280 miles.

Japanese Chief Cabinet Secretary Yoshihide Suga said what appeared to be a North Korean ballistic missile fell within Japan's exclusive maritime economic zone.

“We cannot tolerate such repeated actions from North Korea, and we have lodged a strong protest against North Korea, criticizing them in the strongest form,” Suga said.

There was no immediate comment from North Korea's state controlled media. But the launch followed a report from the North that said leader Kim Jong Un had watched a successful test of a new type of anti-aircraft guided weapon system. It wasn't clear from the report when the test happened.

North Korea is still thought to be several years away from its goal of being able to target U.S. mainland cities with a nuclear ICBM, but each new test puts it closer to success. The North has a strong arsenal of short- and medium-range missiles that target Japan and South Korea and U.S. forces in the region, and it is working to perfect its longer-range missiles.

The Associated Press contributed to this report.