Trump, his son and top members of his campaign advanced a set of conspiracy theories about the vote-tallying process to claim that Democrats were rigging the final count.
Eric Trump tweeted a video, first pushed out by an account associated with the far-right QAnon conspiracy theory, that purported to show someone burning ballots cast for his father. The materials turned out to be sample ballots, and Twitter quickly suspended the original account that circulated the misleading clip.
Maricopa County in Arizona has closed its ballot-counting facility to the media and the public amid safety concerns as supporters of Donald Trump — many of them armed — gathered outside the building, several reporters on the ground have reported.
But poll workers will continue to count ballots and report results amid the developing demonstration outside.
“Staff at the @maricopacounty Elections Department will continue our job, which is to administer elections in the second largest voting jurisdiction in the county,” the Maricopa County Elections Department tweeted in a statement late on Wednesday.
“We will release results again tonight as planned. We thank the [Maricopa County Sheriff’s Office] for doing their job, so we can do ours.”
Arizona GOP Congressman Paul Gosar was pictured among the crowd gathered outside the building.
The protesters in Maricopa County, some of whom were waving Trump flags, have been chanting “Fox News sucks!” and “Count the votes!” for hours.
Fox News and several other media outlets had called the Arizona presidential race late on Election Night for Democratic presidential nominee Joe Biden, but the margin has tightened substantially as mail-in ballots favouring Mr Trump have continued to roll in through Wednesday.
An NBC News correspondent who left the building late Wednesday night reported via Twitter that the crowd “claiming the vote was being stolen from the president had grown larger & louder.”
The demonstration outside the Maricopa County Elections Office follows a salvo of tweets on Wednesday from Mr Trump peddling conspiracy theories and misinformation about ballot-counting as it appeared his Democratic opponent, Mr Biden, was primed to pull away in the Electoral College.
The damage has already been done to the integrity of our system, and to the Presidential Election itself. This is what should be discussed!” the president tweeted shortly after The Associated Press called Michigan in Mr Biden’s favour on Wednesday.
Mr Biden, at 253 projected Electoral College votes in the bag so far, stands just 17 shy of victory.
Arizona carries a prize of 11 electoral votes, which would put Mr Biden just six away from reaching the threshold of 270 to win the presidency.
Members of the press gathered at the Maricopa County Elections Office were told around 10:15pm local time that they needed to clear out of the building even though election workers would stay to finish counting ballots, according to CNN.
Maricopa County is expected to upload the next batch of results at 1:30am on the East Coast, CNN reported.
Heading into Thursday, the third day of ballot-counting, Mr Biden held small leads in both Nevada and Arizona. If he won both, that would net him exactly 270 electoral votes, cinching the victory.
He also has other paths to victory.
By 1am Thursday on the East Coast, Mr Biden had made up considerable ground in the vote counts in Pennsylvania and Georgia.
In a speech on Wednesday, the Democratic former vice president expressed confidence that he would end up with enough electoral votes to win the presidency. Paying tribute to his supporters and the more than 150m Americans who cast votes, Mr Biden declared: “[Tuesday] proved democracy is the heartbeat of this nation.”
In a brief but notably determined statement on Wednesday, delivered alongside running mate Kamala Harris, Mr Biden made clear he was not yet claiming victory.
“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.”
