US President Donald Trump claimed that the available results of the election are a "major fraud" on the American public as he addressed his supporters early Wednesday morning at the White House.
"This is an embarrassment to our country," he said. "We will win this. As far as I'm concerned, we already have."
Concerns had been running high ahead of Tuesday's election that the US president would attempt to claim victory before all the ballots were tallied.
Suggesting that he would reject results favoring his opponent Joe Biden following a drawn-out count, he said his administration wants the law "to be used in a proper manner."
Trump pledged to involve the US Supreme Court in evaluating unfavorable election results, and called for "all voting to stop" although polls had already closed.
"We'll be going to the US Supreme Court," he said, although it was unclear what legal grounds he would use.
"We don't want to find any ballots at four in the morning and add them to the list. We will win this. As far as I'm concerned, we already have," he said.
Critics decry remarks as 'attack' on democracy
Responding to Trump's claims of fraud, Pennsylvania Governor Tom Wolf called the comments a "partisan attack on Pennsylvania's elections, our votes, and democracy."
"Our counties are working tirelessly to process votes as quickly AND as accurately as possible. Pennsylvania will have a fair election and we will count every vote," Wolf tweeted.
Trump also prematurely claimed victory in the key battleground states of Georgia and North Carolina, where ballots are still being counted.
At the time Trump's speech, the election was hinged on a number of swing states that had not yet declared winners, including Michigan, Wisconsin and Pennsylvania.
Biden calls for patience
Trump's comments came after Joe Biden called on his supporters to "keep the faith" and voiced his confidence that his party would claim victory in the polls.
The Democratic presidential candidate spoke to voters on Wednesday after midnight (5 a.m. UTC), telling them "your patience is commendable."
"I'm here to tell you tonight we believe we're on track to win this election," said Biden. He also called on supporters to remain patient through the drawn-out vote counting process, which he warned could drag on beyond Wednesday.
"We knew because of the mail-in vote, it's going to take awhile. We're going to have to be patient until the hard work of counting votes is finished."
Hours after polls closed, a number of key states were still working to count hundreds of thousands of votes, after a large number of mail-in ballots slowed the vote-counting process across the United States.
"We're still in the game in Georgia, although that's not what we expected. We're feeling really good about Wisconsin and Michigan," said Biden. The Democratic candidate also said he would not prematurely declare victory, ahead of official results.
"It's not my place or Donald Trump's place to declare who's won this election. That's the decision of the American people."