US can't accept nuclear North Korea but "diplomacy is the only way to deal with it'

"I cannot imagine a condition under which the United States would accept North Korea as a nuclear power," US Defense Secretary James Mattis said on Saturday in Seoul during a meeting with his counterpart, South Korean Defense Minister Song Young-moo.

The US defense official, however, added that "diplomacy remains the preferred way" to deal with Pyongyang, which comes as an apparent change in the rhetoric of Washington regarding North Korea's nuclear program.

Still, Mattis warned Pyongyang that its military "was no match for the decades-old US-South Korean alliance," in terms of "firepower and cohesiveness" and that "any attack on the US or its allies will be defeated, and any use of nuclear weapons by the North will be met with a massive military response that is effective and overwhelming."
in response to the call of some South Korean conservative politicians to bring back US tactical nuclear weapons that were withdrawn from the Korean Peninsula in the 1990s, both the US and South Korean Defense Ministers rejected the idea.

James Mattis  was on his week-long trip to Asia, which included stops in Thailand and the Philippines.

Meanwhile, according to the latest report of the American-based website NK News, North Korea has conducted mass evacuation exercises in cities and towns across the country, excluding Pyongyang. The drills also included ‘blackout’ exercises, when "whole towns would turn out all the lights at night time so as to avoid illuminating enemy targets."

The outlet suggested that the drills came as "wartime preparations."