Biden predicts victory in US election; Trump sues to stop vote count

Democrat Joe Biden on Wednesday predicted a US election win over Donald Trump, while the Republican incumbent sought to offset a path to re-election with lawsuits and demands for a recount.

Victories in Michigan and Wisconsin gave Biden, a former vice president, a critical boost in the race to obtain 270 electoral votes in the state-by-state Electoral College needed to win the White House.

Trump, who won both states in 2016, now has fewer options to secure a second four-year term.

With the count still underway, he has falsely declared victory, accused the Democrats of trying to steal the election and vowed to fight the states in court.

"It's clear that we're winning enough states to reach (the) 270 electoral votes needed to win the presidency," Biden, appearing with his running mate Kamala Harris, said in his home state of Delaware. "I'm not here to declare that we've won. But I am here to report that when the count is finished we believe we will be the winners."

Trump has spent months seeking to undermine the credibility of the voting process in case he lost and accusing Democrats, without evidence, of seeking to steal the election.

His campaign fought to keep Trump's chances alive with lawsuits in Michigan and Pennsylvania to stop vote counting. It demanded a recount in Wisconsin.

The campaign asked the US Supreme Court to allow Trump to join a pending lawsuit filed by Pennsylvania Republicans over whether the battleground state, which was still counting hundreds of thousands of mail-in ballots, should be permitted to accept late-arriving ballots sent by Election Day on Tuesday.

While fighting to stop the count in states where he feared losing, Trump blasted news organisations that projected losses in Arizona and Nevada, states he thought he should be winning.

Biden said every vote must be counted. "No one's going to take our democracy away from us, not now, not ever. America's come too far. America's fought too many battles, America's endured too much to ever let that happen," he said.

Trump is trying to avoid becoming the first incumbent US president to lose a re-election bid since George H.W. Bush in 1992.

Biden won Michigan by 67,000 votes, or 1.2 per cent, while he was ahead in Wisconsin by just over 20,000 ballots, or 0.6 per cent, according to figures from Edison Research, which projected Biden as the winner in Michigan. Several news outlets projected Biden as the winner in Wisconsin, though Edison did not, citing the pending recount.

Wisconsin law allows a candidate to request a recount if the margin is below 1 per cent, which the Trump campaign immediately said it would do.

In response to the Michigan lawsuit, Ryan Jarvi, a spokesman for the state attorney general, said the elections had been "conducted transparently".

Voting concluded as scheduled on Tuesday night, but many states routinely take days to finish counting ballots. There was a surge in mail-in ballots nationally amid the pandemic. Other closely contested states including Arizona, Georgia, Nevada and North Carolina were still counting votes, leaving the national election outcome uncertain.

At the moment, not including Wisconsin, Biden leads Trump 264 to 214 in Electoral College votes, which are largely based on a state's population.