The United States and China have agreed on a new round of sanctions against North Korea, eliciting a renewed threat by Pyongyang to scrap the armistice that ended the 1950-53 Korean war.

China, for the first time, supported the new sanctions – which relate to its third nuclear test – that “significantly expand” UN measures already in place.

“We support action taken by the council, but we think that action should be proportionate, should be balanced and focused on bringing down the tension and focusing on the diplomatic track,” said Li Baodong, China’s ambassador to the United Nations.

“A strong signal must be sent out that a nuclear test is against the will of the international community,” he added.

The UN Security Council called for an explicit ban on the sale to Pyongyang of items coveted by North Korea’s ruling elite, such as yachts and racing cars, a council diplomat said on Tuesday. The new measures, which the council hopes to vote on by Thursday, also aims to cripple Pyongyang’s ability to move funds around the world, according to Reuters.

In response, North Korea threatened on Tuesday to scrap the Korean armistice and to shut off a military “hotline” with the US and South Korea, the official KCNA news agency said.

Pyongyang also criticized the US-South Korean military exercises, calling it a “systematic act of destruction aimed at the Korean armistice”.