Lan Hong, a former Chinese diplomat, believes China’s long-term security concerns are about maintaining the country’s “global dominant military power”.

“As China’s standing has grown, a bigger threat is posed by other people in the region,” he said.

“The other threat to the sovereignty of China in the south-east has, in fact, been to its military, its navy and air force, because as China has grown stronger in the military, it’s become a target for the likes of Vietnam, the Philippines and Singapore.”

Mr Lan Hong said Beijing had taken steps in recent years to increase international sanctions against North Korea.

“One of those are the UN sanctions aimed at cutting the oil in trade,” he said.

Mr Lan Hong, who was in the U.S. for a recent trip and speaking to the Senate Armed Services Committee, said Chinese leaders hoped to convince President Trump to remove economic sanctions on North Korea.

“They certainly don’t want the tension to escalate, but given they are trying to improve relations with North Korea in the hope that there will be a greater number of sanctions that the new administration would sign off on,” he said.

Mr Trump and Chinese President Xi Jinping spent the weekend at Mar-a-Lago, which Mr North Korea has dubbed the “Winter White House”, while the two agreed to work to ease tensions on the Korean Peninsula.