Facebook and Twitter have placed warnings on a 46-minute video statement released by Donald Trump on Wednesday, in which the president repeats baseless claims of voter fraud in November’s election, which he lost to Joe Biden. President-elect Biden, a veteran Democrat, won the presidential election with 306 electoral college votes, compared with Trump’s 232. However, Trump has refused to concede, and has instead launched – and lost – flimsy legal battles in several states, which experts said appeared aimed at dragging out vote counting and creating a cloud of uncertainty over the electoral process. “This may be the most important speech I’ve ever made,” Trump says in the video, before making lengthy, rambling and baseless claims that America’s electoral system is “under coordinated assault and siege”. Trump, who spoke from the Diplomatic Room, kept up his futile pushback against the election even as state after state certifies its results and as Biden presses ahead with shaping his cabinet in advance of his inauguration on 20 January. Biden received a record 81m votes compared to 74m for Trump. The Democrat also won 306 electoral votes compared to 232 for Trump. The electoral college split matches Trump’s victory over Hillary Clinton four years ago, which he described then as a “landslide”. Trump dug further into his contention of a “rigged election” even though members of his own administration, including the attorney general, William Barr, say that no proof of widespread voter fraud has been uncovered. Courts in multiple battleground states have thrown out a barrage of lawsuits filed on behalf of the president. “This is not just about honoring the votes of 74 million Americans who voted for me,” Trump said. “It’s about ensuring that Americans can have faith in this election. And in all future elections.” The Trump video comes a day after Barr said the US Department of Justice had not uncovered evidence of widespread voter fraud that would change the outcome of the presidential election. In an interview with the Associated Press, Barr said US attorneys and FBI agents had been working to follow up complaints and information but had uncovered no evidence that would change the outcome of the election. “To date, we have not seen fraud on a scale that could have effected a different outcome in the election,” Barr said. Trump campaign lawyers Rudy Giuliani and Jenna Ellis said in a statement: “With the greatest respect to the attorney general, his opinion appears to be without any knowledge or investigation of the substantial irregularities and evidence of systemic fraud.” As the 8 December deadline for states to certify their results approaches, Trump is fast running out of options to contest the outcome of the election. Many of Trump’s claims, including that the US election was subject to widespread “voter fraud”, have been debunked repeatedly in recent weeks. In fact, Christopher Krebs, the director of the Department of Homeland Security’s Cybersecurity and Infrastructure Security Agency, voiced confidence in the integrity of the election ahead of the November vote. And afterward, he knocked down allegations that the count was tainted by fraud. Krebs was fired by Trump weeks ago. The video was released a day after one of Georgia’s top election officials made an impassioned plea to Trump to tone down his rhetoric disputing the election results, saying the president was “inspiring people to commit potential acts of violence”. Gabriel Sterling, a Republican who oversaw the implementation of the state’s new voting system, also issued the stark warning that if Trump and his supporters did not rein in election disinformation then “someone is going to get hurt”. Sterling, the voting systems manager for the Georgia secretary of state’s office, said last week that he had police protection around his home because of threats he received after election results were announced. Trump lost Georgia to Biden by about 13,000 votes. Trump responded to Sterling’s plea by tweeting baseless claims about the Georgia election and criticising the state’s Republican governor, Brian Kemp. Twitter flagged his tweet as “disputed”.