US President-elect Joe Biden defeated incumbent Donald Trump Saturday, ending days of heated anticipation as poll officials tallied pivotal ballots.

Biden won the crucial state of Pennsylvania, and with the victory there surpassed the necessary 270 Electoral College delegates needed to claim the White House, according to The Associated Press and other news organizations.

Biden now holds a commanding 290 delegates after the AP also called Nevada for the president-elect. The states of Georgia, North Carolina, and Alaska remain outstanding several days after Tuesday’s presidential election, but it is now mathematically impossible for Trump to win re-election without a major change in vote counts.

“America, I’m honored that you have chosen me to lead our great country,” the president-elect said on Twitter ahead of public remarks expected for Saturday evening, US time.

“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.”

Biden’s victory makes Trump the first single-term president in nearly three decades. Trump has, however, vowed to pursue legal challenges to the vote totals in several states.

Trump refused to concede shortly after every major news outlet in the US called the race for his opponent, instead lashing out defiantly in a statement distributed by his campaign that claimed the election “is far from over.”

“Joe Biden has not been certified as the winner of any states, let alone any of the highly contested states headed for mandatory recounts, or states where our campaign has valid and legitimate legal challenges,” the outgoing president said. “Legal votes decide who is president, not the news media.”

Trump said his team would begin legal challenges on Monday, but he did not specify in which states the lawsuits would go forward.

The win also makes history with Biden’s running mate, Senator Kamala Harris, now set to become the first woman to serve as US vice president, as well as the first Black person and the first person of Asian descent.

Trump is set to leave office amid a worsening Covid-19 pandemic with the US reporting over 100,000 daily cases since Wednesday.

Over 236,000 people have died during the pandemic, and Biden sought during his campaign to cast the grim fact as disqualifying Trump from receiving a second term in office.

In addition to the stark health crisis, Biden will now have to contend with uniting an American public that has been sharply divided during the White House race, and could further sink into partisan trenches, particularly with the president’s hitherto refusal to concede.

Biden turns 78 two months to the day before Inauguration Day, making him the oldest incoming president in US history. (PNA)