Republican United States President Donald Trump and his Democratic challenger Joe Biden have both claimed to be ahead in the closely fought presidential election, even as the final outcome hinged on a handful of states on Thursday where a flood of mail-in ballots triggered by the raging coronavirus pandemic remained to be counted.
Trump and Biden both won key American states they were expected to win in their bid for a majority in the 538-member Electoral College that determines who wins the race for the White House in Tuesday's election.
But the results in four states -- Georgia, Pennsylvania, North Carolina and Nevada -- was yet to be declared as officials counted millions of votes, some that were cast on Tuesday and many more during weeks of early voting amidst the surging pandemic.
Neither candidate had garned the 270 Electroal College votes needed to win the White House. But Biden's chances were better as he had 253 Electroal College votes compared to 213 won by President Trump, according to latest US media projections.
In the US election, voters decide state-level contests rather than a single, national one. Each US state gets a certain number of Electoral College votes partly based on the size of the population, with a total of 538 up for grabs.
To reach the magic figure of 270 to claim victory, Trump, 74, must win all four remaining battleground states: Georgia, Pennsylvania, North Carolina and Nevada.
There are approximately 90,735 ballots still outstanding in Georgia, Secretary of State Brad Raffensperger's office told CNN. The state has 16 Electoral College votes.
With 71 per cent of mail-in ballots counted in Pennsylvania, officials still needs to count 763,000 of the 2.6 million cast, according to the state's official website. The state has 20 Electoral College votes.
North Carolina has 15 Electoral College votes while Nevada has six.
On Wednesday, Biden, 77, told reporters in Wilmington, Delaware: "When the count is finished, we believe we will be the winners."
"I will govern as an American president. The presidency itself is not a partisan institution."
The incumbent US president said he would go to the Supreme Court to try to have what he called the "voting" stopped, although polls had closed hours earlier and state election officials were continuing the ballots.
"This is a major fraud on our nation," Trump contended, adding, "As far as I'm concerned, I already have won."
In the battleground states key to determining the winner of the election -- Georgia, Michigan and Pennsylvania -- the Trump campaign filed lawsuits on Wednesday over mail ballot handling, while in Wisconsin the Trump team requested a recount.
The Trump campaign said the president would formally request a Wisconsin recount, citing "irregularities in several Wisconsin counties".
Incomplete results indicate the margin between Trump and Biden in Wisconsin is less than one percentage point, which allows a candidate to seek a recount.
The Trump campaign also filed a lawsuit in Michigan to stop counting there because it contended it had been denied "meaningful access" to observe the opening of ballots and the tally.
His campaign asked the Supreme Court to intervene in the ballot counting in Pennsylvania, according to US media reports.
The overall voter turnout in the November 3 presidential election was projected to be the highest in 120 years at 66.9 per cent, according to the US Election Project.
Former US vice president Biden got over 72 million voters, the most won by any presidential candidate ever. President Trump received more than 68 million votes, four million more than he gained in 2016 when he defeated his then Democratic rival Hillary Clinton.
The one of the most divisive and bitter election race was dominated by the coronavirus pandemic, which hit a new record high of 103,000 daily cases in the US on Wednesday, according to the Covid Tracking Project.
The US is the worst-hit nation with over 233,700 deaths and more than 9,486,000 confirmed cases, according to latest data from Johns Hopkins University.
