Democrat Joe Biden has won the critical swing state of Wisconsin but Donald Trump’s campaign said it would request a recount as the tabulation of votes in the US presidential election stretched into Wednesday.

Iran PressAmerica: Joe Biden had won the Midwestern state, which became increasingly important after Dounald Trump had taken Florida and Ohio. Biden also leads in Nevada and Michigan but lags the Trump in Pennsylvania, Georgia and North Carolina, according to AP.

With millions of absentee ballots still to be counted, neither candidate had secured the 270 electoral college votes needed to win the presidency. Biden could reach the threshold by maintaining his leads in Nevada and Michigan, assuming that any recount upheld his victory in Wisconsin.

Shortly before the Wisconsin race was called, the Trump campaign said it would request a recount, which would be automatic in such a narrow race. With 98 per cent of the vote counted, Biden had won 49.4 per cent of the state’s ballots. Trump had secured a narrow victory in Wisconsin in 2016.

Bill Stepien, the Trump campaign manager, said there had been reports of “irregularities” in some Wisconsin counties that raised “serious doubts” about the validity of the result.

“The president is well within the threshold to request a recount and we will immediately do so,” he said.

Preliminary estimates indicate that the turnout in the 2020 US presidential election is unprecedented in the last 120 years since 1900.