US president Donald Trump has issued a stern threat to North Korea, as the rogue nation's state media warned that it would launch a nuclear attack on the US if provoked.
In a pair of tweets aimed at goading China into taking action against the dictatorship, Mr Trump said, "North Korea is looking for trouble", and vowed to "solve the problem" with or without Chinese help.
He also said that China could expect a better trade deal with the US if they worked to neutralise the nuclear threat that North Korea posed.
North Korea is looking for trouble. If China decides to help, that would be great. If not, we will solve the problem without them! U.S.A.
Meanwhile, North Korea's official Rodong Sinmun newspaper said: "Our revolutionary strong army is keenly watching every move by enemy elements with our nuclear sight focused on the US invasionary bases, not only in South Korea and the Pacific operation theatre but also in the US mainland."
The war of words comes as reports firm that China is amassing soldiers on the North Korean border in anticipation of a potential pre-emptive strike from the US.
Mr Trump's tweets represent the President's first public statements on the issue since the US diverted a naval strike force - including the aircraft carrier USS Carl Vinson and three guided-missile destroyers - to the western Pacific Ocean on Saturday.
Meanwhile, North Korea's official Rodong Sinmun newspaper said: "Our revolutionary strong army is keenly watching every move by enemy elements with our nuclear sight focused on the US invasionary bases, not only in South Korea and the Pacific operation theatre but also in the US mainland."
The war of words comes as reports firm that China is amassing soldiers on the North Korean border in anticipation of a potential pre-emptive strike from the US.
Mr Trump's tweets represent the President's first public statements on the issue since the US diverted a naval strike force - including the aircraft carrier USS Carl Vinson and three guided-missile destroyers - to the western Pacific Ocean on Saturday.
North Korea has slammed the US show of force, saying there would be "catastrophic consequences".
In a statement provided to CNN, Pyonyang said it would counter "reckless acts of aggression" no matter what "methods the US wants to take".
The statement said the "current grim situation" justified its "self-defensive and pre-emptive strike capabilities with the nuclear force at the core".
"We will make the US fully accountable for the catastrophic consequences that may be brought about by its highhanded and outrageous acts," the statement said.
Tensions have escalated sharply on the Korean Peninsula since North Korea tested a mid-range ballistic missile last week, while Chinese President Xi Jinping was meeting with Mr Trump in Florida.
The US has sent the armada to the western Pacific in response to the tests and the movement was also timed ahead of the most important day on the isolated nation's calendar, the birthday of the country's founder Kim Il-sung, who is the late grandfather of current leader Kim Jong-un.
Pyongyang is expected to mark the 105th anniversary on Saturday with a provocative display, such as launching a missile or testing a nuclear device.
Mr Trump has threatened unilateral military action against North Korea before. His tweets overnight are more aimed at encouraging action from China, which is the North's only major ally.
CHINESE ARMY BUILD-UP ON NORTH KOREA BORDER: REPORTS The escalating tensions come amid reports that the Chinese army has sent 150,000 troops to the North Korean border in case of military action.
South Korea's Chosun.com reported that medical and back-up units from the People's Liberation Army had been deployed to the Yalu River.
'WE WILL DEFEND OURSELVES BY POWERFUL FORCE' North Korea's foreign ministry and state-run media have both indicated that the nation is prepared to respond to the US's show of force.
An unnamed foreign ministry spokesman said "reckless moves for invading had reached a serious phase".
"We never beg for peace but we will take the toughest counteraction against the provocateurs in order to defend ourselves by powerful force of arms and keep to the road chosen by ourselves," he said in a statement to the KCNA news agency.
The claim has been leant credibility after it was repeated on the front page of China's state-owned Global Times newspaper.