Warning North Korea for its continuous nuclear activities, United States Defence Secretary Jim Mattis on Saturday said that Washington would never accept a "nuclear North Korea".
As per Sputnik reports, Mattis, who was on an overseas trip to South Korea, accused Pyongyang of accelerating threat to its neighbours by illegal and unnecessary missile and nuclear weapons programs.
"Diplomacy remains our preferred course of action. As I have repeatedly emphasised our diplomats are most effective when backed by credible military force in this sort of situation," he said, following a meeting with South Korean Minister of National Defense Song Young-moo.
The Defense Secretary on Friday morning visited the heavily fortified border between North Korea and South Korea known as the Demilitarized Zone (DMZ) amid heightened tensions over the North's nuclear programme.
The US and North Korea have long been engaged in back-and-forth barbs over the latter's threat of a nuclear attack.
North Korea jolted major world leaders when it carried out the strongest of its six-ever nuclear tests in early September, claiming to have used a hydrogen bomb.