US secretary of defence James Mattis has accused North Korea of using nuclear weapons to threaten others with "catastrophe" but said the US remained committed to a diplomatic solution to the Korean nuclear crisis.
"North Korean provocations continue to threaten regional and global security despite unanimous condemnation by the United Nations Security Council, " Mr Mattis said during a visit to Panmunjom inside the heavily weaponised Demilitarised Zone (DMZ) dividing the Korean Peninsula, the Yonhap news agency reported.
“We stand should to shoulder with you and the Korean people in confronting the threats posed by the Kim Jong-un regime . . . Our goal is not war, but rather the complete, verifiable and irreversible denuclearisation of the Korean Peninsula,” he said.
He made his comments ahead of US president Donald Trump's first visit to Asia next week, a trip that includes a stop in South Korea to meet its president Moon Jae-in, as well as Japan, China and Vietnam.
Mr Trump and North Korean leader Kim Jong-un have engaged in an increasingly belligerent war of words. Mr Trump refers to Mr Kim as "Rocket Man" and during a speech last month at the UN, threatened to destroy North Korea if necessary to defend the United States and allies.
Mr Kim has blasted Mr Trump as “a mentally deranged US dotard”.
The DMZ has been in place since the end of the Korean War (1950-53), and North and South Korean troops stand metres apart across one of the most heavily fortified borders in the world. The two Koreas remain technically at war because the conflict ended with an armistice, not a peace treaty.
Mr Mattis pledged his country’s solidarity with its ally South Korea, at whose side the US fought during the war.
He was accompanied during his visit by South Korean defence minister Song Young-moo, who urged the North to stop its "reckless provocations" and resume dialogue as soon as possible.
Mr Song said the North’s nuclear and ballistic missiles were “weapons that can’t be used . . . If it does, it will face retaliation by the strong combined force of South Korea and the US.”
In a separate development, North Korea said it would repatriate a South Korean fishing boat and its crew in a “humanitarian” gesture after the vessel entered the North’s waters.
(Additional reporting: agencies)