The outcome of the US presidential election is on a knife edge, with Donald Trump and his rival Joe Biden neck and neck in key swing states.
Mr Trump, a Republican, claimed to have won and vowed to launch a Supreme Court challenge, baselessly alleging fraud.
Earlier Mr Biden, a Democrat, said he was “on track” to victory.
Millions of votes remain uncounted and no candidate can credibly claim victory as yet. There is no evidence of fraud.
More than 100 million people cast their ballots in early voting before election day on Tuesday – setting US on course for its highest turnout in a century.
With the nation on edge, the final result may not be known for days.
The president is projected to have held the must-win state of Florida – a major boost to his re-election bid.
But Mr Biden could snatch Arizona, a once reliably conservative state. Fox News and the Associated Press have projected Mr Biden will win that state and CBS News, the BBC’s US partner, said it was leaning the Democrat’s way.
A loss for Mr Trump in that once reliably Republican state would be a potentially serious setback.
Other key states such as Georgia, Pennsylvania, Wisconsin, Michigan and North Carolina are toss-ups.
The BBC projects Mr Trump will win another conservative sunbelt state, Texas, where the Biden campaign had dreamed of an upset victory.
The Rust Belt battlegrounds of Pennsylvania, Michigan and Wisconsin – which propelled Mr Trump to the White House four years ago – still look as though they could tip either way.
Pennsylvania, along with Florida, is considered a must-win for Mr Trump if he is to stave off defeat.
Cliffhanger counts are also under way in two more critical swing states on the East Coast, Georgia and North Carolina.
No surprises have emerged yet in the other states.