Talks aimed at cooling tensions between the US and China have ended in a "deal", according to US President Donald Trump.

He said China had agreed to supply US companies with magnets and rare earth metals, while the US would walk back its threats to revoke visas of Chinese students.

"Our deal with China is done, subject to final approval from President Xi and me," Trump wrote on his media platform Truth Social.

It followed two days of intense talks in London to resolve conflicts that had emerged since the two sides agreed a truce in May, after a rapid escalation of tariffs had nearly paralysed trade between the world's two largest economies.