Democratic presidential candidate Joe Biden and his running mate Senator Kamala Harris inched closer to the magic figure of 270 electoral college votes amid indications that incumbent Republican President Donald Trump was moving ahead with his plan to mount a massive legal challenge that is likely to slow down declaration of final results.

By late on Wednesday night in Washington (IST 11.00 am, Thursday), multiple media outlets, including The New York Times, reported that Joe Biden had won Michigan and Wisconsin, two key swing states that President Trump won four years ago.

Bidens’ victories meant he was on the threshold of crossing the magic mark of 270 electoral college votes and becoming President-elect. The projected numbers so far are: Joe Biden 253, Donald Trump 214.

Biden, who received more than 71 million votes, the most in history, was joined by Harris at an afternoon press conference during which he said he expected to win the verdict of the American people.

“I will govern as an American president,” Biden said. “There will be no red states and blue states when we win. Just the United States of America,” he said in sharp contrast to Trump’s false declaration on Wednesday that he had already won the election even though millions of votes were yet to be counted.

But as the Trump campaign’s path to victory appeared to be narrowing, it claimed victory in the battleground states of Pennsylvania, Michigan, North Carolina and Georgia.

Its managers said that it would seek a recount in Wisconsin and then announced that it had taken legal action seeking to halt the vote count in Michigan, one of a flurry of lawsuits that included joining an action challenging the extension of ballot deadlines in Pennsylvania and filing another seeking to segregate late absentee ballots in Georgia.

"We have claimed, for Electoral Vote purposes, the Commonwealth of Pennsylvania (which won't allow legal observers), the State of Georgia and the State of North Carolina, each one of which has a BIG Trump lead. Additionally, we hereby claim the State of Michigan if, in fact ... there was a large number of secretly dumped ballots as has been widely reported!" the president said in a series of tweets.

Biden exuded confidence in winning the race. "Keep faith in the process and in each other. Together, we will win this," he said in a tweet.

One source of Biden’s resilience lay in the nature of the votes still to be counted. Many are mail-in ballots, which favour him because the Democratic Party spent months promoting the message of submitting votes in advance, while Trump encouraged his voters to turn out on Election Day. And in Pennsylvania, many of the uncounted votes are from populous urban and suburban areas that tend to vote heavily for Democrats.

The big surprise of the 2020 US election, billed as the election of a lifetime, is not the early red-flag raised by Trump against the process, but that the vote did not produce the overwhelming verdict against him that the Democrats had wanted.

Opinion polls had given Biden a strong lead nationwide for months but had shown tighter races in battleground states. Biden’s hopes of a decisive early victory were dashed when Trump won the battlegrounds of Florida, Ohio and Texas.

Trump’s strong performance in Florida, a must-win state for his re-election, was powered by his improved numbers with Latinos. For months, there had been complaints from Democratic Latino activists that Biden was ignoring Hispanic voters and lavishing attention instead on Black voters in big Midwestern cities.

A national exit poll showed that about 11 per cent of African Americans, 31 per cent of Hispanics and 30 per cent of Asian Americans voted for Trump, up 3 percentage points from 2016 in all three groups.

The close election underscored the political polarisation in the US which was experiencing a pandemic that has killed more than 232,000 Americans and wiped away millions of jobs.

The two candidates, Biden and Trump, spent months portraying dramatically different visions of the nation’s future, including on racial justice and voters, and voters responded in huge numbers, with more than 100 million people casting votes ahead of election day.