Pyongyang accused on Tuesday the United States of laying the ground for a possible preemptive strike against it.
It said that Washington was seeking to aggravate the situation on the divided Korean peninsula by "deploying large nuclear assets" nearby.
"In view of the nature and scale of US military reinforcements, they are designed to make a preemptive strike against the DPRK," North Korean diplomat Ju Yong Chol told the UN-sponsored Conference on Disarmament, referring to his country's official name the Democratic People's Republic of Korea.
"US officials including the defense secretary and the CIA director repeatedly talked about DPRK nuclear and missile threat to justify their argument for a military option and a new concept of a so-called 'bloody nose', a limited preemptive strike on the DPRK is under consideration within the US administration," Ju said.
The accusation came hours before US Vice President Mike Pence was set to arrive in South Korea to attend the opening of the Pyeongchang Winter Olympic Games that kick off on Friday.
Pence departed Monday for Alaska, Japan and South Korea, aiming to ensure North Korea does not "hijack" the games as it participates on a joint team with the South, in the view of the White House.
He will hold symbolic events of his own to highlight the North's human rights abuses and nuclear ambitions, according to White House officials who spoke on condition of anonymity because they were not authorized to preview the trip publicly.
"We'll be telling the truth about North Korea at every stop," Pence told reporters after touring missile defense facilities Monday that monitor and could respond to a launch by the North.
"We'll be ensuring that whatever cooperation that's existing between North and South Korea today on Olympic teams does not cloud the reality of a regime that must continue to be isolated by the world community."
In Japan, he will meet with Prime Minster Shinzo Abe and US service members. In Korea, Pence will visit a memorial to the 46 South Korean sailors killed in a 2010 torpedo attack attributed to the North, and hold meetings with President Moon Jae-in.
"Missile defense is essential to our national defense," Pence said before a briefing with US Northern Command at Joint Base Elmendorf-Richardson in Anchorage, Alaska. He touted the coming deployment of an additional 20 ground-based interceptors that would respond to an enemy launch.
Pence did not rule out the possibility of meeting with the North Korean delegation during his South Korea trip.
"Let me say President Trump has said he always believes in talking, but I haven't requested any meeting," he said. "But we'll see what happens."
North Korea is sending its nominal head of state, Kim Jong Nam— the highest-level visitor to the South from the North in recent memory.
Pence said his message, if he met any officials from the North, would be the same as it has been in public.
"And that is that North Korea must once and for all abandon its nuclear weapons program and ballistic missile ambitions," he added.
