朝鲜未显示任何去核迹象

A week after U.S. President Donald Trump proclaimed North Korea no longer posed a nuclear threat, his top military official cautioned there are no new signs Pyongyang is doing anything to denuclearize.

"I'm not aware of it," U.S. Defense Secretary Jim Mattis told reporters Wednesday at the Pentagon. "I wouldn't expect that at this point," he added. "[We're] obviously at the very front end of the process. The detailed negotiations have not begun."

Trump declared the threat of a nuclear North Korea had ended June 13, following his summit in Singapore with North Korean leader Kim Jong Un.

"Everybody can now feel much safer than the day I took office," Trump tweeted upon returning to the U.S. "There is no longer a nuclear threat from North Korea. Meeting with Kim Jong Un was an interesting and very positive experience. North Korea has great potential for the future!"

But a day later, U.S. Secretary of State Mike Pompeo warned tough sanctions would remain in place until the U.S. can verify Pyongyang's "complete denuclearization."

Pompeo has said he expects to return to North Korea in the near future to hammer out details of the U.S. deal with Pyongyang. As part of that agreement, President Trump has pledged to end U.S. and South Korea "war games."

South Korean officials this week said they had agreed to suspend the annual Freedom Guardian exercise with the U.S., originally scheduled to take place in August.