Results from the western swing state of Nevada could be known on Thursday morning, after pollsters stopped counting ballots on election day and planned to return to them on Wednesday.
Nevada officials originally hoped to release results at 9.45pm Pacific time, or just after midnight on election night eastern, but they will instead be delayed until 9am on Thursday, midday eastern time and 5pm UK time.
Joe Biden currently has a narrow lead over Donald Trump in Nevada, with more ballots still to be counted
The state said it had counted all votes cast in-person either on election day or beforehand and all mail-in ballots received before election day. However it still needs to count postal votes received on 4 November, while it will also accept mail-in ballots arriving as late as next Tuesday, as long as they were posted before the polls closed.
It means the full number of votes won by Donald Trump and Joe Biden might not be fully known until next Tuesday, although close to 1.2million votes had been counted as of Wednesday morning.
Nevada's secretary of state's office said it was 'difficult to estimate' how many ballots were left to count as it sent every voter in the state a ballot in the post, even if people subsequently chose to vote in person.
But while Biden has a slim lead of fewer than 8,000 votes as of the latest count, around 75,000 mail ballots could still need to be counted in Clark County, home to Las Vegas and close to three-quarters of the state's population.
Polling workers in North Las Vegas, Nevada, after the polls closed on election day yesterday
Biden is currently winning this part of the state by 422,762 votes to 362,573, and Jon Ralston, editor of The Nevada Independent, said the 337,000 previously counted absentee ballots from the county 'have dramatically favoured the Democrats so far by more than two to one', potentially giving the Democrat some breathing space.
Meanwhile the Trump campaign also lost a last-minute bid to try and stop mail ballots in Clark Country from being processed using machines which automatically verify signatures, after their claim that the process was opaque was thrown out by the state's Supreme Court on election day.
Initial results in the state were also likely delayed by the fact 30 polling spots were allowed to stay open for an extra hour following a court order, after they faced 'technical problems'. No results are allowed to be posted until all ballots have been cast in Nevada.How Biden or Trump could both still win fair and square TODAY without election ending up in court
Donald Trump and Joe Biden have plausible paths to claiming victory in the White House race on Wednesday without going to court.
But they depend on a series of factors falling into place.
As of 5 am Joe Biden was on 238 Electoral College votes and Donald Trump on 213.
Undecided were Nevada - widely expected to break for Biden - and Alaska, seen as safely in Trump's column. That would put them on 244 and 216.
But undecided are Georgia (16 votes), North Carolina (15), Wisconsin (10), Michigan (16), a single vote from Maine's undeclared Congressional district and the big prize of Pennsylvania with 20 votes.
Here are the ways that the election could be decided on Wednesday - without any court battles.
HOW BIDEN CAN WIN ON WEDNESDAY
SCENARIO ONE: MICHIGAN AND WISCONSIN GO FOR BIDEN
This is the ending to the election which involves the fewest states and could break most rapidly.
Combined the two mid-western states have 26 votes. That would put Joe Biden on the vital 270 figure.
Wisconsin's results could come as early as 9am Wednesday.
Michigan's results are less clear but the Secretary of State said Tuesday that she hopes to provide 'a very clear picture, if not a final picture' by Wednesday night.
As of 6am Biden was slightly behind Trump, at 51.3% to 47%.
Currently almost 20% of votes are still to be counted and they are mail-in ballots, which are expected to favor Biden.
Detroit, the state's biggest city and a hub of Democratic voters, won't have its results known until sometime Wednesday as it experiences record levels of turnout, a good sign for Biden.
Turnout in Motor City, where Biden campaigned with Barack Obama on Friday, is expected to hit 55 per cent – that's up seven points over the 48 per cent who voted in 2016.
The record number of votes means full results will be known Wednesday, City Clerk Janice Winfrey announced Tuesday night.
Statewide, 3.3 million absentee ballots had been cast, Michigan Secretary of State Jocelyn Benson said, but results will take time.
'We're on track to be in a position to potentially see a full result of every tabulation in the next 24 hours,' she announced.
Trump won the state by taking the suburbs - the Macomb and Monroe counties outside of Detroit - but he also won working-class areas in like Michigan's Upper Peninsula, which has many white working-class voters.
Biden has concentrated on winning African American voters in the state in urban areas like Flint.