As crowds rushed into the streets of Washington and other cities in exuberant celebration after US networks declared Biden the winner, here are some reactions from across the globe:
Germany
“Congratulations!” said Chancellor Angela Merkel. “I wish luck and success from the bottom of my heart.
“Our transatlantic friendship is irreplaceable if we want to overcome the great challenges of our times,” she said in a tweet issued by a government spokesman.
France
French President Emmanuel Macron tweeted: “The Americans have chosen their President. Congratulations @JoeBiden and @KamalaHarris! We have a lot to do to overcome today’s challenges. Let’s work together!”
Britain
British Prime Minister Boris Johnson congratulated Biden “on his election as President of the US and Kamala Harris on her historic achievement.
“The US is our most important ally and I look forward to working closely together on our shared priorities, from climate change to trade and security.”
European Union
In a joint statement, EU Commission President Ursula von der Leyen and Charles Michel, president of the European Council, which represents the leaders of EU member states, said: “We take note of the latest development in the electoral process.
“On this basis the EU congratulates President-elect Joe Biden and Vice-President-elect Kamala Harris on reaching enough Electoral Votes.”
Nato
Nato chief Jens Stoltenberg described Biden as a “strong supporter of our Alliance”.
Stoltenberg, who often had to adapt to President Donald Trump making unexpected announcements about US troop drawdowns from Nato deployments, said in a tweet he looked forward to working with Biden.
“A strong Nato is good for both North America and Europe,” he said.
Canada
Canada’s Prime Minister Justin Trudeau said: “I look forward to working with President-elect Biden, Vice-President-elect Harris, their administration, and the US Congress as we tackle the world’s greatest challenges together.”
Barack Obama
Former US president Barack Obama hailed Biden’s win as “historic and decisive” and appealed to Americans to overcome bitter divides and “find some common ground”.
“Once every vote is counted, President-Elect Biden and Vice-President-Elect Harris will have won a historic and decisive victory,” Obama, Donald Trump’s White House predecessor, said in a statement.
Ireland
The republic’s prime minister Micheal Martin was one of the first to take to Twitter, tweeting:
“I want to congratulate the new President Elect of the USA @JoeBiden.
“Joe Biden has been a true friend of this nation throughout his life and I look forward to working with him in the years ahead. I also look forward to welcoming him back home when the circumstances allow!”
Greece
Prime Minister, Kyriakos Mitsotakis tweeted: “Congratulations to US President-Elect @JoeBiden. Joe Biden has been a true friend of Greece and I’m certain that under his presidency the relationship between our countries will grow even stronger.”
Italy
Prime Minister Giuseppe Conte tweeted:
“Congratulations to the American people and institutions for an outstanding turnout of democratic vitality. We are ready to work with the President-elect @JoeBiden to make the transatlantic relationship stronger.
“The US can count on Italy as a solid Ally and a strategic partner.”
Spain
Prime Minister Pedro Sanchez tweeted:
“The American people have chosen the 46th President of the US. Congratulations @JoeBiden and @KamalaHarris. We wish you good luck and all the best. We are looking forward to cooperating with you to tackle the challenges ahead of us.”
India
“Congratulations @JoeBiden on your spectacular victory!” Prime Minister Narendra Modi tweeted.
In a separate tweet to Biden’s running mate Kamala Harris, whose mother was Indian, Modi wrote: “Your success is pathbreaking, and a matter of immense pride not just for your chittis, but also for all Indian-Americans.”
“Chitti” is a Tamil term of endearment for the younger sisters of one’s mother, which Harris used in her acceptance of the Democratic nomination for vice-president.
She is the first woman of colour elected to the US vice-presidency.
Nigeria
In his congratulations, President Muhammadu Buhari, leader of Africa’s most populous nation, called for “greater engagement” with the continent.
He said he looked forward to “enhanced cooperation between Nigeria and the US, especially at economic, diplomatic and political levels, including especially on the war against terrorism”.
Ukraine
President Volodymyr Zelensky tweeted in English:
“Congratulations to Joe Biden, Kamala Harris! Ukraine is optimistic about the future of the strategic partnership with the US.
“Ukraine and the USA have always collaborated on security, trade, investment, democracy, fight against corruption. Our friendship becomes only stronger!”
South Africa
President Cyril Ramaphosa said on Twitter his government looked forward to “working with you and deepening our bonds of friendship and cooperation”.
Iraq
President Barham Saleh extended “warmest congratulations” to Biden, describing him as “a friend and trusted partner in the cause of building a better Iraq.
“We look forward to working to achieve our common goals and strengthening peace and stability in the entire Middle East”.
Egypt
President Abdel Fattah al-Sisi said Egypt, the most populous Arab country, looked forward to “strengthening strategic bilateral ties between Egypt and the US in the interest of both countries and peoples”.
UAE
“Congratulations to @JoeBiden and @KamalaHarris on winning the US elections. Our sincere wishes for further development and prosperity for the American people.
“The UAE and USA are friends and allies with a strong historic partnership that we look forward to strengthening together,” tweeted Abu Dhabi Crown Prince Sheikh Mohammed bin Zayed Al-Nahyan.