TORONTO -- U.S. president-elect Joe Biden celebrated his win over Donald Trump as 鈥渃lear" and "convincing鈥 in a hometown victory speech as he vowed to waste no time cracking down on the COVID-19 pandemic and called on Americans to set aside their differences once and for all.

鈥淭his is a time to heal in America,鈥 Biden said Saturday night on stage in Wilmington, Delaware as a drive-in rally of masked supporters cheered.

鈥淟et鈥檚 give each other a chance. It鈥檚 time to put away the harsh rhetoric, to lower the temperature, to see each other again, to listen to each other again.鈥

Biden鈥檚 speech came roughly eight hours after he was declared winner of the U.S. election, thanks in large part to Midwestern and suburban voters who helped him deny Trump four more years in the White House. He won both the electoral college and the popular vote, and is the first presidential candidate in history to surpass 74 million votes.

At 77, Biden is the oldest person ever elected U.S. president.

Hailing the record-breaking turnout, Biden promised to be a president for all Americans, no matter if they voted for him or not.

鈥淚鈥檝e pledged to be a president who seeks not to divide, but unify. Who doesn鈥檛 see red states and blue states, who only sees the United States.鈥

Combatting COVID-19 was a core message in Biden鈥檚 campaign. He announced that, starting Monday, he plans to assemble a task force of scientists and experts who will help him confront the crisis as soon as he鈥檚 inaugurated in January.

鈥淚 will spare no effort, none, or any commitment to turn around this pandemic,鈥 he said.

Biden was introduced by vice president-elect Kamala Harris, who makes history as the first woman and the first person of colour elected to the nation鈥檚 second-highest office.

Harris said that, while she may be the first female vice-president, she won鈥檛 be the last.

鈥淏ecause every little girl watching tonight sees that this is a country of possibilities. And to the children of our country: regardless of your gender, your country has sent you a clear message. Dream with ambition. Lead with conviction, and see yourselves in a way that others may not simply because they鈥檝e never seen it before,鈥 she said.

鈥淎nd to the American people, no matter who you voted for, I will strive to be a president like Joe was to president Obama: loyal, honest and prepared, waking up every day and thinking of you and your family.鈥

Biden reached 290 electoral votes on Saturday morning after The Associated Press called Pennsylvania and Nevada in his favour. AP鈥檚 electoral college vote count includes Biden winning Arizona, which other major news networks had yet to declare as they await the results from about 450,000 outstanding ballots.

Trump鈥檚 loss adds his name to a short list of one-term presidents. The last incumbent president to lose his re-election bid was Republican George H. W. Bush in 1992.

Trump has not conceded the election.

The declaration of a winner comes after five tense days of ballot counting that saw an early Trump lead give way to Biden in a number of key swing states once mail-in ballots began to be tallied.

As electoral maps started shifting from red to blue, a distrustful Trump made repeated, baseless claims the election was being 鈥渟tolen鈥 through widespread voter fraud.

鈥淚 WON THE ELECTION, GOT 71,000,000 LEGAL VOTES,鈥 Trump tweeted more than five hours after news networks declared Biden the winner with more than 74.9 million votes.

The president offered no evidence to support his fabricated accusations as he tried to cast doubt on the legitimacy of the ballot-counting process and launched multiple lawsuits in several states, including Georgia, Michigan and Pennsylvania. He also vowed to push for a recount in Wisconsin, where Biden was declared the winner on Wednesday.

The race was a nail-biter in large part due to an unprecedented number of mail-in ballots, many of which have taken days to count. In Pennsylvania, for example, mail-in ballots could not legally be opened and counted until election day.

The surge in mail-in ballots was driven, in large part, by the COVID-19 pandemic, which persuaded many voters to cast their votes from afar to avoid large crowds on election day. These mailed ballots largely favoured Biden after Trump had spent the months leading up to the election urging his supporters against voting by mail.

In addition to its impact on mail-in ballots, the pandemic coloured other aspects of the campaign. Biden consistently attacked Trump鈥檚 record on the crisis, accusing Trump of a failure of leadership that cost hundreds of thousands of American lives. Meanwhile, Trump accused Biden of not having a plan to handle the crisis and of wanting to shut down the entire economy to control the spread, a claim Biden repeatedly denied.

Even after Trump, his wife Melania, and numerous other members of his inner circle contracted the virus in early October, the president continued to downplay the severity of the global pandemic.

The federal government鈥檚 response to the health emergency as well as Trump鈥檚 insistence on holding large rallies for his supporters throughout the campaign drew sharp criticism from the country鈥檚 top infectious disease expert, Dr. Anthony Fauci, who became more outspoken in his opposition to the president鈥檚 handling of the pandemic in the latter days of the election.

Biden, conversely, shunned in-person rallies and held online and drive-in events for his supporters. He also expressed support for Fauci throughout the campaign and promised to listen to the nation鈥檚 top health experts for advice on curbing the spread of COVID-19 should he be elected.

Along with promising to 鈥渟hut down the virus,鈥 and not the the economy as Trump accused throughout the campaign, Biden campaigned on a message to 鈥渂uild back better.鈥 He promised to restore decency to the White House while also prioritizing issues such as climate change and racial justice.

On the racial justice front, Biden depended on a strong turnout among Black voters in cities such as Philadelphia, Detroit, and Milwaukee, to bolster his support in key states.

While Trump has been accused of racist remarks and inflaming racial divides across the U.S., Biden has faced his own share of criticism for his past record on Black rights, including his treatment of Anita Hill at Clarence Thomas' Supreme Court confirmation hearing in 1991 and his support for a crime bill in 1994 that has been blamed for putting a generation of Black men in prison.

During the campaign, however, Biden prioritized racial justice issues, expressing support for the Black Lives Matter movement and acknowledging that systemic racism exists and should be addressed.

On climate change and environmental issues, Biden and Trump offered wildly different plans for the future. Trump has described climate change as a 鈥渉oax,鈥 and removed the U.S. from the 2015 Paris Agreement 鈥 a global pact aimed at reducing greenhouse gas emissions to curb Earth鈥檚 rising temperatures.

Biden, on the other hand, has promised to have the U.S. rejoin the Paris Agreement in addition to reinstating Obama-era emissions rules. He has also vowed to invest in clean energy and environmental research to address what he has described as a 鈥渃limate emergency.鈥

In addition to an expected reversal on climate policies, the shift in power will undoubtedly shake up the United States鈥 relationship with its closest trading partner: Canada. Trump repeatedly targeted Canada with tariffs on steel and aluminum amid negotiations on the new NAFTA.

Trump also personally attacked Prime Minister Justin Trudeau, calling him two-faced in the wake of a video of Trudeau speaking candidly to other world leaders about the president. 

With files from The Associated Press