The Trump campaign stepped up its efforts to challenge the results of the November 3 election saying it intended to file a petition for a recount in two Wisconsin counties: Milwaukee and Dane.

Trump paid about $3 million for the recounts in the two counties overnight on Tuesday and planned to submit the necessary paperwork to set off the recount on Wednesday, the campaign said in a statement.

Joe Biden, the projected winner of the 2020 U.S. election, defeated U.S. President Donald Trump by 20,608 votes in the state. Biden received 577,455 votes compared with 213,157 for Trump in the two heavily Democratic Wisconsin counties.

Despite not tabling any evidence of irregularities and state election officials saying there were none, Trump's campaign labelled the two counties as the sight of the "worst irregularities".

Jim Troupis, a Wisconsin attorney who is working with the Trump campaign, said the people of Wisconsin deserved to know whether their election processes "worked in a legal and transparent way".

"Regrettably, the integrity of the election results cannot be trusted without a recount in these two counties and uniform enforcement of Wisconsin absentee ballot requirements. We will not know the true results of the election until only the legal ballots cast are counted," Troupis said.

Once officially approved by the elections commission chair, the recount may begin as soon as Thursday and not after Saturday. The process would have to be completed by December 1.

Recounts in Wisconsin and across the country have historically resulted in very few vote changes. A presidential recount in Wisconsin four years ago saw Trump garner only an additional 131 votes.

(With input from agencies)