North Korea has gone two months without a provocative missile or nuclear test from North Korea, after a recording-breaking nine-month period in which Pyongyang fired 15 missiles and exploded one nuclear bomb.

It could be a good sign, or it could mean nothing, Pentagon officials say.

“So long as they stop testing, stop developing, they don’t export their weapons, there would be opportunity for talks,” Defense Secretary Jim Mattis told reporters traveling with him to U.S. Northern Command in Colorado Thursday.

Asked by reporters this week if he had a sense as to why North Korea hadn't launched anything in weeks, Mattis refused to speculate. “Let me know if you figure it out,” he joked.

China is dispatching an envoy to meet with North Korean officials Friday, but at the Pentagon, chief spokesperson Dana White said it’s too soon to read anything into the pause in provocative actions.

“I think it's perilous to predict anything about what North Korea does or doesn't do,” White said. “But we're continuing to monitor the situation.”

One day after President Trump said China’s President Xi Jinping agreed with the U.S. position that there should be no freeze in U.S. military exercises in the region in return for a freeze in North Korean missile tests, a Chinese Foreign Ministry spokesman said China believes what it calls “a dual suspension” would actually be the best way to get negotiations going.

The U.S. military just began a 10-day exercise with Japanese maritime forces in the waters off Okinawa and has long said the many routine exercises are vital to keeping the U.S. and its allies prepared to counter any threat from the North.

“For forward-deployed forces, exercises are a critical component of readiness,” said Lt. Gen. Kenneth McKenzie, at a Pentagon briefing. “They do, in fact, assure our partners. They're not necessarily aimed at anyone. But they also, I think, exercise a powerful deterring effect by the fact that they're occurring.”

North Korea may not have fired any missiles for two months, but it hasn’t muzzled its verbal pyrotechnics.

Pyongyang's state media this week called Trump a coward who deserves to die.

"He should know that he is just a hideous criminal sentenced to death by the Korean people," said an editorial in the Rodong Sinmun newspaper.