US President Donald Trump has announced that he would head to the Supreme Court claiming victory for the US election even as vote counting was ongoing on Wednesday.

Trump, who spoke from the ceremonial East Room of the White House, claimed there was electoral fraud in the crucial but divisive election but failed to avail any proof to that effect.

"We did win this election. This is a fraud on the American public," Trump said.

The Republican, who is seeking a second and final term, is in a neck-and-neck race with Democratic Party challenger Joe Biden but wants the apex court to stop voting and counting.

Trump is opposed to mail-in ballots, which reportedly favour Biden, which can be accepted legally by state poll boards after Tuesday’s vote as long as they were submitted in time.

The presidential race is tight and the early voting ballots could prove crucial in determining the victor, with more Democrats believed to have cast their mail-in ballots more than Republicans.

More than 100 million ballots were cast before the Tuesday Election Day even as many businesses boarded up for fear of eruption of post-election violence.

During his night press briefing, Trump declared that he had won the poll claiming the vote results had been halted and raised issue with the continuing voting and counting.

"We were getting ready for a big celebration. We were winning everything and all of a sudden it was just called off.

"This is a fraud on the American public. This is an embarrassment to our country. We were getting ready to win this election. Frankly, we did win this election.”

The US president vowed to head to the Supreme Court to ensure the process is stopped.

"We will be going to the US Supreme Court. We want all voting to stop."