United States President Donald Trump and his supporters refused to accept defeat and pushed unfounded suspicions that widespread voter fraud was preventing him from winning a second term after former Vice President Joe Biden won the elections.

Trump's supporters demonstrated at state capitols across the U.S. on Saturday, chanting "This isn't over!" and "Stop the steal," and echoing their candidate's baseless claims that the Democrats won by means of cheating.

From Atlanta to Austin, Bismarck, Boise, and Phoenix, a few dozen to a few thousand people - some openly brandishing weapons - protested the news of Biden's victory after over three tension-filled days of vote-counting put the presidential Democratic bet at the top. Clashes erupted in some U.S. cities.

Outside the capitol building in the long-dominated Republican citadel of Georgia, chants of "lock him up" reverberated from among an estimated 1,000 Trump loyalists. Others shouted "Fake news!" The streets outside the capitol were filled with Trump flags.

Emphasizing the sour feelings on both sides of the country's wide political divide, anti-Trump demonstrators in Washington jeered, shouted obscenities, and yelled "Loser! Loser!" and flashed the dirty finger to Trump's convoy as the president made his way back to the Oval Office from a golf outing Saturday. Two signs placed in front of the president's Washington hotel read: "Don't be a sore loser" and "Face Reality."

According to Trump's aides, he had no plans to immediately make the kind of concession speech that for many years has been traditional in past presidential polls, and his team said they would continue to wage a legal fight across the nation. Trump said Biden was trying to "falsely pose" as the winner.

Biden made an appeal to Trump's supporters in his first speech after winning the elections. In Wilmington, Delaware Saturday night, he said "this is the time to heal in America" and vowed to be a leader who will represent even those who did not vote for him.

Meanwhile, contrary to the allegations of Trump's supporters, there's been no solid proof of any serious vote trickery. And a number of elected Republican officials around the U.S. started to keep themselves away from Trump and even called on him to accept the results in a graceful manner.

Biden becomes the 46th U.S. president. He won Pennsylvania on Saturday to surpass the 270 electoral votes required to win the presidency. He also secured Michigan, Wisconsin, Nevada, and Arizona, en route to making Trump the first sitting president since George H.W. Bush to lose his bid for a second term.