The Trump campaign has launched a number of lawsuits demanding a halt to counts. But in states like Arizona and Nevada, where Mr Trump is currently marginally behind, his supporters are demanding that counting continues.
The campaign filed a lawsuit in Michigan to stop counting there because it contended it had been denied “meaningful access” to observe the opening of ballots and the tally.
In Detroit, Michigan, police were called on Wednesday afternoon to guard the doors to a vote-counting facility as some protesters outside demanded access to monitor the process. According to the Detroit Free Press, there were already some 200 people observing the vote inside the building.
The Trump campaign also filed two lawsuits in Pennsylvania to halt all vote counting “until there is meaningful transparency”. The president has a three-point lead in the Keystone State, but many thousands of votes remain to be counted.
Mr Trump has also started legal action against Georgia to halt the vote count there. His campaign said a Republican poll observer in the southern state had witnessed 53 late absentee ballots being illegally added to a pile of votes in Chatham County.
And in Wisconsin, Mr Trump’s campaign said the president would formally request a recount, citing “irregularities in several Wisconsin counties”.
Incomplete results indicate the margin between Mr Trump and Mr Biden in Wisconsin is less than one percentage point, which allows a candidate to seek a recount.
As things stand, Mr Biden is ahead by more than 20,000 votes. Election experts say recounts typically change tallies by only a few hundred.
In 2016, Mr Trump’s wins in Wisconsin, Michigan and Pennsylvania sealed his victory and took him to the White House.
In the early hours of Wednesday, the president claimed he had won the election despite many uncounted votes remaining. The speech brought strong criticism from both Democrats and Republicans.
Mr Trump also said he was prepared to take the election to the Supreme Court, and his campaign is asking Republican donors to help fund legal challenges. Such challenges start at a state level but could eventually lead to the top court in the US.
Republican National Committee Chairwoman Ronna McDaniel said: “The fight’s not over. We’re in it.”
Mr Biden’s running mate, Kamala Harris, tweeted asking supporters to contribute $5 to help pay for litigation that could “stretch on for weeks”.
Biden campaign senior legal adviser Bob Bauer said there were no grounds for Mr Trump to invalidate lawful ballots.
