US President Donald Trump has arrived in China seeking help to rein in North Korea after warning its leader that the nuclear weapons he is developing "are not making you safer, they are putting your regime in grave danger."
Mr Trump used some of his toughest language yet against North Korea in a wide-ranging address in Seoul that lodged specific accusations of chilling human rights abuses.
He called on countries around the world to isolate Pyongyang by denying it "any form of support, supply or acceptance."
"Do not underestimate us and do not try us," Mr Trump told North Korea as he wrapped up a visit to South Korea with a speech to the National Assembly before heading to Beijing, where he was making his first official visit.
Mr Trump painted a dystopian picture of the reclusive North, saying people were suffering in "gulags" and some bribed government officials to work as "slaves" overseas rather than live under the government at home.
He offered no evidence to support those accusations.
Mr Trump's return to harsh, uncompromising language against North Korea came a day after he appeared to dial back the bellicose rhetoric that had fueled fears across east Asia of the risk of military conflict.
Yesterday, Mr Trump had even offered a diplomatic opening to North Korea to "make a deal."
US President Donald Trump has stern warning for North Korea - "Do not underestimate us and do not try us". pic.twitter.com/OnUVL5Iz4F
— RTÉ News (@rtenews) November 8, 2017
In today’s speech he went on the attack mostly, but did promise a "path to a much better future" for North Korea if it stopped developing ballistic missiles and agreed to "complete, verifiable and total denuclearisation", something Pyongyang has vowed never to do.
"We will not allow American cities to be threatened with destruction. We will not be intimidated," he told South Korean politicians.
"And we will not let the worst atrocities in history be repeated here, on this ground we fought and died to secure.
"The world cannot tolerate the menace of a rogue regime that threatens it with nuclear devastation," Mr Trump said, speaking as three US aircraft carrier groups sailed to the Western Pacific for exercises - a rare show of such US naval force in the region.
The North defends its weapons programs as a necessary defense against what it says are US plans to invade.
The United States, which has 28,500 troops in South Korea, a legacy of the 1950-53 Korean war, denies any such intention.
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In Beijing, Mr Trump and Chinese President Xi Jinping resumed their "bromance" struck in April at Mr Trump's Mar-a-Lago resort in Florida, making small talk as they toured the Forbidden City with their wives.
Mr Trump has threatened action over China's wide trade surplus with the US and called on Beijing to do more to rein in ally and neighbour North Korea, but has expressed admiration for Mr Xi, calling him a friend, and held off on imposing trade measures.
Mr Trump will ask China to abide by United Nations resolutions and cut financial links with North Korea, a senior White House official said on the plane from Seoul.
Meanwhile a meeting between Mr Trump and Russian President Vladimir Putin at the Asia-Pacific Economic Cooperation summit in Vietnam this week is "highly likely," Kremlin spokesman Dmitry Peskov has said.
Mr Peskov added that the two sides were still trying to agree on the best time and format for the meeting.
