The first projected results are coming in as millions of Americans vote in an historic election that could put Donald Trump back in the White House or make Kamala Harris the first woman to become US president.
The two candidates were neck and neck in the opinion polls after a bitter campaign that saw two assassination attempts against Republican Mr Trump as well as the shock withdrawal of President Joe Biden.
In around 100 days since replacing Mr Biden, Ms Harris has found her feet and mounted a fierce challenge to her opponent.
Follow live: First projected results in
The final hours of voting are under way and polls have already closed in many states, including Georgia – one of a handful of battleground states that could decide the election.
What results are in so far?
Voting is still happening in some states, while counting is now under way in a slew of states where polls have already closed.
While not all the votes have been counted, a winner can be projected in a number of states.
Ms Harris is projected to have won Vermont, Massachusetts, Delaware and Maryland.
Mr Trump is projected to have won Florida, Arkansas, South Carolina, Kentucky, Indiana, Missouri, Oklahoma, Tennessee, Alabama and West Virginia.
None of the seven battleground states have yet been projected. It’s thought that Georgia could be the first to declare, possibly as early as 10pm (3am UK time).
Voters are not just selecting a president. Control of both the House of Representatives and the Senate are also up for grabs, with all seats in the House and one-third of those in the Senate up before voters.
With most races still not yet called, NBC News has projected that Republicans have gained a Senate seat in West Virginia. It had been held by independent Senator and former Democrat, Joe Manchin.
How the vote works
As well as those lining up at polling booths on Tuesday, tens of millions of Americans cast early ballots – voting by post or in person before today.
To become president, the winning candidate needs 270 electoral votes or more, with each state carrying a different number of votes.
If the polls predicting a close race are correct, the election will likely come down to a few battleground states: Arizona, Georgia, Michigan, Nevada, North Carolina, Pennsylvania and Wisconsin.
With some races perhaps coming down to thousands of votes, it could be days before a definitive result is known.
The FBI reported that there had been “non-credible” bomb threats to several states, resulting in some polling stations staying open later. The agency said some of the threats came from Russian email domains. The Russian embassy said accusations of interference were “malicious slander”.
Read more:
An easy guide to the US election
What Trump or Harris victories would mean for UK
Trump or Harris
Former president Mr Trump, 78, voted in Palm Beach, Florida, near his Mar-a-Lago club.
Wearing his trademark red “Make America Great Again” baseball cap, he said at the polling station that he was feeling “very confident”.
“I hear we’re doing very well,” he said. “It looks like Republicans have shown up in force.”
Elon Musk, the world’s richest man and Trump donor, said he will watch results unfold with the former president.
In the meantime, Ms Harris, the 60-year-old Democratic vice president, did radio interviews in the battleground states of Pennsylvania, Georgia and North Carolina.