China declined Monday to congratulate Joe Biden as the winner of the US presidential election, saying the outcome of the vote was still to be determined.

While incumbent Donald Trump has yet to concede and has launched several legal challenges, many world leaders congratulated Biden and running mate Kamala Harris after the Democrats were declared winners at the weekend and spontaneous celebrations erupted across American cities.

Trump's four years in the White House have been marked by a costly trade war and increasingly icy relations with China, with the two powers sparring over areas from blame for the Covid-19 pandemic to Beijing's human rights record in Xinjiang and Hong Kong.

China -- among a handful of major countries including Russia and Mexico that has not congratulated the President-Elect -- said Monday it had "noticed that Mr Biden declared he is the winner of the election."

"Our understanding is that the outcome of the election will be determined in accordance with US laws and procedures," foreign ministry spokesman Wang Wenbin told press at a regular briefing.

After declining to acknowledge Biden's victory despite repeated questions from reporters, Wang said: "We hope the new US government can meet China halfway."

Trump has refused to concede defeat, complaining in a tweet on Sunday, "Since when does the Lamestream Media call who our next president will be?"