China, the president tweeted on Monday, “may be exerting negative pressure on a deal because of our posture on Chinese Trade - Hope Not!”
"I have confidence that Kim Jong Un will honour the contract we signed &, even more importantly, our handshake," he added. "We agreed to the denuclearisation of North Korea."
Mr Trump recently placed tariffs on billions of dollars worth of Chinese goods, accusing the country of stealing American intellectual property. Beijing retaliated with matching tariffs on $34bn worth of US imports, setting off a trade conflict between the world’s two largest economies.
It was unclear why Mr Trump accused the country of intervening in a possible deal with North Korea. The accusation came after two days of talks between Secretary of State Mike Pompeo and North Korean officials, as the two countries tried to hammer out the specifics of a denuclearisation pledge that Mr Trump and Mr Kim signed at a summit in Singapore last month.
Mr Pompeo called the latest talks “productive,” but North Korea’s Foreign Ministry denounced them as "deeply regrettable," accusing the US of forcing a “unilateral and gangster-like demand for denuclearisation”.
The two days of talks, the Foreign Ministry said, "brought us in a dangerous situation where we may be shaken in our unshakable will for denuclearisation, rather than consolidating trust between [North Korea] and the US".
While some saw the North's criticism as a negotiating tactic, Senator Lindsey Graham suggested China may have played a role in the about-face.
"We are in a fight with China," Mr Graham, a member of the Senate Armed Services Committee and occasional friend of the president, told Fox News. “They cheat and President Trump wants to change the economic relationship with China.”
He added: “There’s no doubt in my mind that it's the Chinese pulling a North Koreans back.”
China is North Korea’s largest trading partner and advocate in the region. Mr Kim visited Chinese President Xi Jinping after the Singapore summit last month – his third visit of the year – and agreed to deepen ties and strengthen communication between the two countries.
Mr Trump claimed North Korea was "no longer a nuclear threat," after the Singapore summit in June, where Mr Kim signed an agreement reaffirming his "firm and unwavering commitment to the complete denuclearisation of the Korean peninsula".
But Mr Pompeo appears to have had little success tying the North to any concrete steps towards this goal, and recent intelligence reports suggest the country has not actually stopped producing fuel for its nuclear weapons.
Asked about North Korea's harsh comments this weekend, Mr Pompeo told reporters: “When we spoke to them about denuclearisation, they did not push back."
"The road ahead will be difficult and challenging and we know that critics will try to minimise the work that we've achieved," he added.
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