President Donald Trump's administration has demanded that China take part in talks on a successor to the New START treaty, which caps the nuclear warheads of the United States and Russia -- the two Cold War-era superpowers.

Beijing said in response that it would only join the talks if the US reduced its arsenal to match China's much smaller nuclear deterrent, prompting Washington to again issue a fresh invitation to the talks on Thursday.

But Chinese foreign ministry spokesman Zhao Lijian poured cold water on the idea during a Friday press briefing.

"China's opposition of the so-called trilateral arms control negotiations is very clear," he said.

"However, the US continues to pester China, even distorting China's position."

Zhao said Washington's proposal for trilateral negotiations was "neither serious nor sincere", calling on it to instead respond to Russia's call for an extension of the treaty and further reduce its own nuclear arsenal.