US Election: Donald Trump asks for donations to fight 'radical left' in email to supporters

United States President Donald Trump. Photo / AP

United States President Donald Trump says "radical Democrats" are trying to steal the election and has asked for donations to fight them.

Trump and Democratic challenger Joe Biden remain locked in a tight presidential race - so tight a result might be days away.

Drama erupted tonight with Biden telling supporters "we're on track" to win the election but "we will have to be patient" until all votes are counted. He said a result might be known tomorrow morning (US time) but "it may take a little longer".

Moments later Trump tweeted "we are up big but they are trying to steal the election. We will never let them do it ..."

He said votes cannot be cast after the polls have closed, adding that he would make a statement tonight.

Emails, signed by Trump, are being sent to Republican party supporters tonight urging them to donate to their cause.

The email says they are going to "win big" but goes after the "fake news media and their Democrat partners" who refuse to give up the race.

U.S. President Donald Trump. Photo / Getty Images

"They will try to do whatever it takes to keep us from winning, and that's why I need you to step up," one of numerous recently sent emails says.

"They don't want another four more years of American greatness. They want to rip the power away from the people and put it in the hands of the DC Swamp.

"They don't want you to be in control of your country anymore.

"We need to fight back!"

The emails ask for donations from $5 to $20 or any amount for the cause.

The emails say every patriot will need to step up and defend the results when the Republican party and Trump win the election.

"Contribute $5 immediately to fight back and defend your President from the Radical Left."