Joe Biden on Saturday defeated Donald Trump in the presidential election to become the 46th president of the United States, as the incumbent rushed to reject the outcome saying that the “election is far from over” and threatened further legal challenges.

The Associated Press declared Joe Biden the winner of a grueling campaign for the American presidency four days after elections were held in the country. “He will lead a polarized nation through a historic collision of health, economic and social crises,” AP said.

CNN and NBC News were among the television networks that called the race in his favour, minutes after projecting that he had won the key state of Pennsylvania, securing its 20 electoral votes and crossing the 270-mark needed to win the presidency.

Biden tweeted his gratitude at being elected the president. “America, I’m honored that you have chosen me to lead our great country. The work ahead of us will be hard, but I promise you this: I will be a President for all Americans — whether you voted for me or not. I will keep the faith that you have placed in me,” he tweeted.

With this victory, Kamala Harris made history as the first woman, the first Black American and the first Asian American vice-president of America. She is also expected to be the candidate for the Democratic nomination in 2024.

Even as Biden had failed to flip key states of Florida, Texas and Iowa, he had won battleground states of Michigan and Wisconsin, tightening his grip on the top post.

The Democrats’ victory comes amid claims of a rigged election by the Donald Trump led Republican Party. Trump, refusing to concede defeat, said that Joe Biden was “rushing to falsely pose as the winner” after television networks declared the Democrat’s victory.

“We all know why Joe Biden is rushing to falsely pose as the winner, and why his media allies are trying so hard to help him: they don’t want the truth to be exposed,” Trump said. “The simple fact is this election is far from over,” he added.

“Joe Biden should not wrongfully claim the office of the President. I could make that claim also. Legal proceedings are just now beginning!” Trump had tweeted earlier in the day. “I won this election, by a lot!” he said in another tweet just hours before losing the White House. The tweet has been flagged by Twitter and labelled ‘misleading’.