WASHINGTON: US Secretary of State Rex Tillerson on Wednesday (Jun 21) urged Chinese officials to apply greater diplomatic and economic pressure on North Korea to force Pyongyang to rein in its nuclear weapons programme.
Tillerson's remarks came after he and Pentagon chief Jim Mattis met with the Chinese visitors at the State Department, where Mattis said he saw scope for an improved defense relationship.
The extent to which Beijing can influence Pyongyang is a key issue in trying to defuse the North Korea crisis, and Tillerson's remarks came the day after President Donald Trump appeared to suggest China's President Xi Jinping had come up short in efforts to lean on Kim Jong-Un's regime.
Calling North Korea the "top security threat" to the United States, Tillerson said China has a "diplomatic responsibility to exert much greater economic and diplomatic pressure on the regime if they want to prevent further escalation in the region."
Trump - who frequently denounced China on the campaign trail - has turned to Beijing to help pressure its ally North Korea, prompting concern among Asian partners that America might go easy on the South China Sea territorial dispute.
But on Tuesday, Trump sent a tweet suggesting Xi's efforts had not borne fruit.
"While I greatly appreciate the efforts of President Xi & China to help with North Korea, it has not worked out. At least I know China tried!" Trump tweeted.
He did not elaborate on what might happen next if China, by far the North's most important trading and diplomatic partner, is out of ideas.
Tillerson said the US and Chinese officials had agreed that companies from both countries should not do business with any UN-designated North Korean entities.
In Beijing, officials insisted that they have not given up hope of influencing Pyongyang and that the problem is not China's alone.
Foreign ministry spokesman Geng Shuang said China was not the "focus and the crux" of the crisis.
"In order to resolve the Korean peninsula nuclear issue, China has been making unremitting efforts and we have been playing an important and constructive role," Geng said.
Last month, Beijing and Washington signed a limited deal to open new markets for each other's exports, and a long-standing friend of the Chinese leadership, Iowa Governor Terry Branstad, was confirmed as US ambassador.
But tensions remain - particularly over China's building of artificial islands in disputed South China Sea waters.
"Secretary Mattis and I were clear that the US position remains unchanged," Tillerson said.
"We oppose changes to the status quo of the past through the militarization of outposts in the South China Sea and excessive maritime claims unsupported by international law."
Still, Mattis encouraged greater communication with the Chinese military and said it was important to look to areas of expanded cooperation, including some sort of officer exchange programme to "improve transparency and mutual understanding."
Despite international condemnation and sanctions, North Korea has a small nuclear arsenal and is developing nuclear-capable ballistic missiles that threaten Japan and South Korea - and one day could even hit some US cities.
Washington has some 28,000 troops deployed in South Korea and a naval armada in the region.
PRISONER IN COMA
Trump has made halting the North Korean nuclear threat his number one foreign policy priority, putting aside concerns over trade and currency manipulation to seek Beijing's help in facing down Kim.
China has tightened controls on trade in North Korean coal, but many doubt it will fully enforce any sanctions that might threaten the stability of its unpredictable neighbour.
Separately, Mattis blasted Pyongyang's treatment of Otto Warmbier, a 22-year-old student who died on Monday after being evacuated in a coma from detention in North Korea.
His release last week initially seemed a gesture of goodwill by Pyongyang, but it quickly turned sour when it was revealed that Warmbier had been in a coma for some time.
"We see a young man go over there healthy and, (after) a minor act of mischief, come home dead, basically ... this goes beyond any kind of understanding of law and order, of humanity, of responsibility towards any human being," Mattis said.
"What you're seeing, I think, is the American people's frustration with a regime that provokes and provokes and provokes, and basically plays outside the rules."