Donald Trump's campaign has responded to Twitter flagging a tweet from the president as "misleading", after he suggested rivals were trying to "steal" the election.

Trump tweeted: "We are up BIG, but they are trying to STEAL the Election," shortly after his rival Joe Biden told supporters he expected to win.

Trump 2020 Communications Director Tim Murtaugh said: "Silicon Valley continues on its mission to censor and silence the president of the United States."

Trump, who has repeatedly questioned the integrity of the US electoral process in this cycle, offered no evidence for his claim.