Commenting on this, Rodong Sinmun Saturday says:

The U.S. nuclear threat to the DPRK has reached its climax.

As already known, the U.S. imperialists launched a joint military drill simulating a preemptive attack on the DPRK in the East of Korea, in collusion with Japan and the south Korean puppet forces under the pretext of coping with the "north's provocation and threat." Two U.S. nuclear carrier strike groups are involved in the drill. B-1Bs conducted a provocative drill of dropping mock nukes in the sky above south Korea.

It is against this backdrop that the U.S. brought its nuclear sub to the south Korean port. This shows that the U.S. is to unhesitatingly provoke a nuclear war against the DPRK while maximizing the military pressure on it.

Civilian evacuation happens on the eve of a war.

The U.S. noisily talked about "solution through dialogue and negotiations", asserting it would neither topple the government of the DPRK nor invade it but allow its social system.

This is just hypocrisy to cover up its scenario for aggression. It only shows that its scenario for provoking a nuclear war has reached a more risky phase.