United States President Donald Trump appeared to acknowledge Sunday that Democratic candidate and president-elect Joe Biden won the U.S. election. However, he said he wouldn't concede.

Trump's statements in tweets included several allegations about the Nov. 3 polls. He said he would keep trying to overturn the outcome.

"He won because the ballot was rigged," Trump said - something he had not said before publicly. This was taken as a sign he was accepting his electoral loss. However, Trump - golfing for a second consecutive - later backtracked, tweeting "I concede NOTHING!"

Trump has launched numerous lawsuits in several states but hasn't provided proof of fraud.

Biden emerged victorious by winning a trio of key states and surpassed the 270 electoral vote requirement. Biden so far recorded 78.8 million votes - the most ever. Trump recorded 73 million votes.

Trump and his Republican allies are spending more time and energy fighting alleged fraud than containing the coronavirus that has claimed the lives of more than 244,000 Americans and counting, the Guardian reported.

Trump tweeted there were no vote watchers or observers allowed and that the votes were tabulated by "radical left privately owned company Dominion" using faulty equipment. He also took a shot at the news media for alleged fake stories.

Trump's tweets were flagged by Twitter as promoting confusion and misinformation: election watchers from both sides were present in every election site.

According to electoral officials, the U.S. presidential election was the "most secure in American history" and there was "no evidence that any voting system removed, lost or changed votes or was in any way compromised," the BBC reported.