Thousands of ballots are still left to be counted.

The outcome of the US presidential election remained in the balance on Friday as a handful of battleground states complete their vote counts and thousands of ballots are still left to be counted.

Former Vice President and Democrat Joe Biden overtook Republican President Donald Trump in the number of ballots counted in the battleground, a must-win state for Trump that has long been a Republican stronghold. Biden now has a 917-vote advantage.

As Biden moved closer to winning the White House, Trump adopted a fighting posture, making false claims to undermine a vote that was not going his way.

Biden has racked up at least 264 of the 270 electoral votes that he needs. Donald Trump has amassed 214 electoral votes so far, and is still in contention in several states that would afford the Republican incumbent a path to re-election.

States yet to finalise winner

• Alaska – 3 votes (Trump leading convincingly)
• Nevada – 6 votes (Biden leading with thin margin)
• Pennsylvania – 20 votes (Trump leading with thin margin)
• North Carolina – 15 votes (Trump leading)
• Georgia – 16 votes (Biden leading with thin margin)

Expected to report final vote counts on Thursday night or Friday are Georgia (16 electoral votes), North Carolina (15), and Nevada (6).

However, mail-in ballots sent on or before Election Day in North Carolina can be counted until November 12.

Three days after Election Day, neither candidate had amassed the votes needed to win the White House. But Biden’s victories in the Great Lakes states left him at 264, meaning he was one battleground state away — any would do — from becoming president-elect.

By flipping yet another critical battleground state that Trump won four years ago, Biden placed himself in a comfortable lead, with only 6 electoral votes shy of the presidency.

Biden could reach the magic number to gain the White House with a win in either Georgia, North Carolina and Nevada, if he keeps Arizona. Trump needs to capture all three to stay competitive.

Nevada, where Biden is favoured, could put him precisely at the number needed to win, if he keeps Arizona. With more than 89 per cent of the vote counted, Biden was leading by less than 11,500 votes.

However, Pennsylvania is the biggest prize remaining, with 20 electoral votes. In the battle ground state of Georgia, Biden pulled ahead by 917 votes, according to AP, as counting continued.

Much of the delay has resulted from a flood of mail-in ballots due to the coronavirus pandemic — and those votes have tended to favour Democrats. If Biden’s lead in Arizona holds, and he wins Nevada or Georgia, he would pass the threshold of 270 electoral votes.

Should Trump hold North Carolina and Georgia but lose Arizona, he must take Nevada as well as Pennsylvania to win.

Simply winning Pennsylvania — where Trump leads but faces a possible onslaught of pro-Biden mailed ballots — will not be enough for the president, even if he takes Alaska’s three electoral votes as expected.

Much to Trump’s chagrin, Pennsylvania has decided to allow mailed ballots sent by Election Day but received up to three days afterwards to be counted. Authorities expect to complete the count by Friday.

Another factor that could keep the battle alive: the Trump campaign has unleashed a legal blitz in key states vital to the incumbent’s re-election.

It has sued to disqualify late-arriving ballots in Pennsylvania, sued in Nevada and Georgia over alleged irregularities, and has demanded a recount in Wisconsin.