Donald Trump has taken to Twitter to threaten North Korea, writing that the country is "looking for trouble", and that America may step in to "solve the problem".
The messages came as Kim Jong-un's regime said it was “ready for war“, and the country's state media warned of a nuclear attack against the United States should America take any military action against them.
Mr Trump is seeking to pressure China to rein in its rogue neighbour. He tweeted that he had told Xi Jinping, the country's president, who made a state visit to the US last week, that "a trade deal with the US will be far better" if Beijing solves the "North Korea problem".
I explained to the President of China that a trade deal with the U.S. will be far better for them if they solve the North Korean problem!— Donald J. Trump (@realDonaldTrump) April 11, 2017
China and South Korea agreed at a meeting on Monday to impose tougher sanctions on North Korea should it carry out further nuclear or long-range missile tests. But it remains hesitant to commit to military action.
Pyongyang's threats came as the Trump administration dispatched a US Navy strike group to the Korean peninsula, following concerns that Kim Jong-un’s regime may soon conduct a sixth nuclear test.
North Korea has been testing military hardware with increasing frequency in recent months, much to the alarm of its neighbours in Japan and South Korea and in violation of UN resolutions.
The re-routing of the US aircraft carrier Carl Vinson and three guided-missile destroyers and cruisers from Australia to the West Pacific was seen as a sign of America's determination to halt the regime's nuclear ambitions.
It also follows a decision by the US president to launch a missile strike against the Syrian regime - with whom North Korea has friendly relations - following a chemical weapons attack that killed dozens of civilians in the country.
Rex Tillerson, the US Secretary of State, said the Syrian missile strikes were a warning to any nation that failed to comply with international laws - comments which were seen as a thinly-veiled threat to Pyongyang.
"If you violate international agreements, if you fail to live up to commitments, if you become a threat to others, at some point a response is likely to be undertaken," Mr Tillerson told ABC's "This Week”, without mentioning North Korea by name.
A North Korean foreign ministry spokesman warned: "We will hold the US wholly accountable for the catastrophic consequences to be entailed by its outrageous actions."
He called Washington's decision "reckless" and said the regime was "ready to react to any mode of war" should the US take military action. North Korea's official Rodong Sinmun newspaper wrote in an editorial that: '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'.
Beijing fears any potential conflict in the region would result in pro-US troops on its border, and also cause a huge refugee crisis in it’s north-east.
Some South Korean newspapers reported that Beijing had moved 150,000 troops to its border with North Korea for “unforeseen contingencies”.
But a foreign ministry spokeswoman said she was not aware of the reported troop movements, and Kim Hong-Kyun, South Korea’s chief nuclear envoy said there was no mention of any military option in his talks with the Chinese on Monday.
The regime will mark several major anniversaries this month, including the 105th birthday of its founding leader on Saturday, and major tests are often carried out on such occasions.
Additional reporting by Christine Wei