Donald Trump has baselessly claimed that the Democrats are trying to "steal" the election - and alleged he could lose because of "major fraud".
In a rant at the White House, he claimed he would go to the Supreme Court, claiming that a group of "sad" opponents were trying to "disenfranchise" his supporters.
The President has outperformed much of the national polling but Democrat Joe Biden is still a narrow favourite to win the White House.
Most states have gone the same way as 2016 with all eyes now on the key battleground states of Wisconsin, North Carolina, Georgia, Michigan and Pennsylvania.
The counting of votes could take days and a contentious decision could well end up being thrown to the courts.
Mr Biden entered polling day with multiple paths to victory, while Mr Trump, playing catch-up in a number of battleground states, had a narrower but still feasible road to clinch 270 electoral college votes.
Donald Trump said that “millions and millions” had voted for him, but said: “A very small group of people are trying to disenfranchise that group, but we won’t stand for it”.
He admitted defeat in Arizona was “possible”, but declared: “We don’t need it, that was just a state we would have got that would have been nice.”
Trump said he would go to the US Supreme Court, saying: “This is a fraud on the American public, this is an embarrassment. We were getting ready to win this election. Frankly, we did win this election.
“This is a major fraud on our nation.”
He added: "We want the law to be used in a proper manner, so we'll be going to the US Supreme Court. We want all voting to stop, we don't want them to find any ballots at 4am in the morning.
"We'll win this, as far as I'm concerned we already have."
