Joe Biden has vowed to unify Americans and heal deep divides across the country in his first speech since being named US President-elect.
He pledged to "work with all my heart to win the confidence of the whole people" and said now was the time to "give each other a chance".
He said: "It's time to put away the harsh rhetoric, lower the temperature, see each other again and listen to each other again."
Kamala Harris, the Vice President-elect, introduced Mr Biden at their drive-in rally in Wilmington, Delaware, and, before he took to the stage, praised officials who oversaw election counts.
She said: "You have protected the integrity of our democracy".
Ms Harris is the first woman to be elected Vice President and the first person of colour in the role.
"While I may be the first woman in this office, I will not be the last - because every little girl watching tonight sees that this is a country of possibilities.
Mr Biden is projected to be the 46th President of the United States after a nail-biting race.
The Democratic candidate gained an unbeatable lead in Pennsylvania yesterday, taking its 20 Electoral College votes and past the 270 needed to win the White House.
He said: "I pledge to be a president who seeks not to divide but to unify; who doesn't see red states and blue states - only sees the United States.
"To make progress, we have to stop treating our opponents as enemies. They are not our enemies, they are Americans."
A new day in America has come. Tune in as Vice President-Elect @KamalaHarris and I address the nation. https://t.co/d38F58DHu8
— Joe Biden (@JoeBiden) November 8, 2020
Coronavirus was a major feature of his speech, while Mr Biden vowed to improve the country's international reputation, as well as to build prosperity, protect people's access to healthcare, root out systemic racism, save the climate and defend democracy.
Meanwhile, Mr Trump is refusing to concede and has vowed to launch legal action, challenging the legitimacy of the result by claiming - without evidence - voter fraud and ballot stuffing on a mass scale.
He was playing golf when the announcement was made, and has since proclaimed "I WON THE ELECTION" on Twitter.
World leaders have already sent congratulations, with Taoiseach Micheál Martin saying that Joe Biden will be "the most Irish President since JFK".
Congratulations to my friends, @JoeBiden and @KamalaHarris — our next President and Vice President of the United States. pic.twitter.com/febgqxUi1y
— Barack Obama (@BarackObama) November 7, 2020
Barack Obama, whom Mr Biden served as vice-president under, has warned the US "remains deeply and bitterly divided", so Americans should "lower the temperature and find some common ground".
Mr Biden has already launched his transition planning, so he can hit the ground running when he takes office in a few months.
After being inaugurated on January 20th, he will officially become the president and US commander-in-chief.
Additional reporting by IRN