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.
No candidate can credibly claim to have won as yet, and both campaigns said they had potential paths to victory.
Mr. Biden’s campaign said the race was “moving to a conclusion in our favor”.
But Mr. Trump, a Republican, claimed to have won and vowed to launch a Supreme Court challenge, without providing evidence of fraud.
Several key states are expected to finish counting by the end of Wednesday but the election may not be decided for days.
The Biden campaign said it expected to win because several states would be called for them on Wednesday or Thursday, but the Trump campaign said it was confident that the maths was in its favor.
The US is on course for the highest electoral turnout in a century. More than 100 million people cast their ballots in early voting before election day, and tens of millions more added their vote on Tuesday.
What are the results so far?
Mr. Trump has defied the pre-election polls to do better than predicted, but Mr Biden has a narrow lead in several key states.
In the US election, voters decide state-level contests rather than an overall, single, national one.
To be elected president, a candidate must win at least 270 votes in what is called the electoral college. Each US state gets a certain number of votes partly based on its population and there are a total of 538 up for grabs.