U.S. President Donald Trump for the first time Sunday acknowledged that Democrat Joe Biden “won” the presidential election against him nearly two weeks ago but continued to make baseless claims that he lost because the vote was rigged against him. The Republican president has declined to formally concede the election to the former vice president even as all major U.S. news media organizations have said for a week that Biden amassed more than the necessary 270-majority in the 538-member Electoral College to win the presidency and be inaugurated on January 20. President-elect Joe Biden speaks Nov. 10, 2020, in Wilmington, Del.In one of a string of Twitter comments, Trump said of Biden, “He won because the Election was Rigged.” Trump went on to make unfounded accusations about the election, saying, “NO VOTE WATCHERS OR OBSERVERS allowed, vote tabulated by a Radical Left privately owned company, Dominion, with a bad reputation & bum equipment that couldn’t even qualify for Texas (which I won by a lot!), the Fake & Silent Media, & more!” He won because the Election was Rigged. NO VOTE WATCHERS OR OBSERVERS allowed, vote tabulated by a Radical Left privately owned company, Dominion, with a bad reputation & bum equipment that couldn’t even qualify for Texas (which I won by a lot!), the Fake & Silent Media, & more! FILE – Republican canvas observer Ed White, center, and Democratic canvas observer Janne Kelhart watch as Lehigh County workers count ballots, in Allentown, Pennsylvania.Some of the disputes involved such small numbers of disputed ballots that even if Trump had prevailed, it would not have overturned Biden’s victories in individual states. Trump’s refusal to acknowledge Biden’s victory in the highly contentious election is unprecedented in modern U.S. politics, although there is no law saying he must concede. Losing U.S. presidential candidates for decades have offered their congratulations to the winners. While declining to formally concede, Trump has also blocked his administration’s officials and government agencies from cooperating with the president-elect’s team on its transition to power or provide Biden with the President’s Daily Brief, a compendium of the U.S. intelligence community’s latest assessment of potential security threats from around the world. Biden has been meeting with his advisers on forming a new government and  considering possible nominees to his Cabinet, as he plans to do again on Sunday.FILE – Then-Vice President Joe Biden is joined by Ebola Response Coordinator Ron Klain in the Eisenhower Executive Office Building on the White House complex in Washington, Nov. 13, 2014.Last week, Biden named a long-time aide, Ron Klain, to be his White House chief of staff, considered to be a key gatekeeper for advice and face-to-face meetings with U.S. presidents.