The United States pressed China to exert more economic and diplomatic pressure on North Korea to help rein in its nuclear and missile programmes during a round of high-level talks in Washington.

The meeting on Wednesday of top US and Chinese diplomats and defence chiefs was held a day after President Donald Trump said Chinese efforts to use its leverage with Pyongyang had failed, raising fresh doubts about his administration’s strategy for countering the threat from North Korea.

“We reiterated to China that they have a diplomatic responsibility to exert much greater economic and diplomatic pressure on the regime if they want to prevent further escalation in the region,” US Secretary of State Rex Tillerson told reporters at a joint news conference with Defense Secretary Jim Mattis.

Mattis vowed to “continue to take necessary measures to defend ourselves and our allies” against North Korea, which is working to develop a nuclear-tipped missile capable of hitting the US.

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But with the long-standing option of pre-emptive military attacks seen as far too risky for now, Trump’s aides are stressing economic and diplomatic pressure.

Tillerson said Trump would make a state visit to China this year, and Mattis said both sides agreed to expand military-to-military ties, signalling the new administration’s determination to continue efforts to improve relations between the world’s two largest economies, despite frustration over North Korea.

Trump on Wednesday said the US had a “great relationship with China”.

North Korea topped the agenda at the newly established Diplomatic and Security Dialogue, which paired Tillerson and Mattis with Chinese State Councillor Yang Jiechi and General Fang Fenghui, chief of joint staff of the People’s Liberation Army.

While the US officials stressed agreement on the goal of North Korean denuclearisation, the talks also dealt with China’s sweeping territorial claims in the South China Sea, with the Americans reaffirming opposition to Beijing’s militarisation of islands it is building in the strategic waterway.

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Tillerson urged China to help crack down on illicit North Korean activities that fund its nuclear and missile programmes. Tillerson stressed the need to choke off funding sources including money laundering, labour export, and computer hacking.

“Countries around the world and in the UN Security Council are joining in this effort, and we hope China will do their part as well,” he said.

China’s Foreign Ministry said earlier Beijing had made “unremitting efforts” to resolve tensions on the Korean Peninsula for its own interests, not due to external pressure.