- German Chancellor Angela Merkel said she was looking forward to working with Biden and said the transatlantic relationship is "irreplaceable."
- Indian Prime Minister Narendra Modi said of Vice President-elect Harris, who is the daughter of an Indian mother and a Jamaican father, that her "success is pathbreaking."
- U.K. Prime Minister Boris Johnson said the U.S. is Britain's most important ally.
WASHINGTON — Leaders from around the world congratulated President-elect Joe Biden and Vice President-elect Kamala Harris Saturday.
U.K. Prime Minister Boris Johnson tweeted his congratulations, calling Harris' accomplishment of becoming the first woman and person of color elected to the vice presidency a "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," he wrote.
In a pair of tweets, Indian Prime Minister Narendra Modi also congratulated Biden and Harris.
Modi said of Harris, who is the daughter of an Indian mother and a Jamaican father, that her "success is pathbreaking." He also added that her success was of immense pride for all Indian-Americans.
"I am confident that the vibrant India-US ties will get even stronger with your support and leadership," Modi wrote.
German Chancellor Angela Merkel and Belgian Prime Minister Alexander De Croo were also among those to congratulate Harris on her historic achievement.
In a statement, Merkel added, "Congratulations! The American citizens have made their decision," Merkel said in a statement. "I am looking forward to working with President Biden in the future. Our transatlantic friendship is irreplaceable if we want to master the great challenges of our time."
Canadian Prime Minister Justin Trudeau wrote, "Our two countries are close friends, partners, and allies. We share a relationship that's unique on the world stage. I'm really looking forward to working together and building on that with you both."
In a statement, the Canadian leader said he would work with the United States to "advance peace and inclusion, economic prosperity, and climate action around the world".
NATO Secretary-General Jens Stoltenberg congratulated Biden, calling him a "strong supporter of NATO and the transatlantic relationship.
"US leadership is as important as ever in an unpredictable world, and I look forward to working very closely with President-elect Biden, Vice President-elect Kamala Harris and the new administration to further strengthen the bond between North America and Europe," he said.
"A strong NATO is good for North America and good for Europe."
European Commission President Ursula von der Leyen said she "warmly" congratulated Biden in a statement on Twitter and said, "The European Commission stands ready to intensify cooperation with the new Administration and the new Congress to address pressing challenges we face."
French President Emmanuel Macron wrote in a tweet: "The Americans have chosen their President. We have a lot to do to overcome today's challenges. Let's work together!"
And in Paris, the city's mayor reacted on Twitter by writing "Welcome back America!"
"While we are about to celebrate the 5th anniversary of the Paris Agreement, this victory symbolizes our need to act together more than ever, in view of climate emergency," Paris Mayor Anne Hidalgo wrote.
From the United Arab Emirates, Abu Dhabi Crown Prince Mohammed bin Zayed al-Nahyan congratulated Biden and Harris on Saturday via tweet.
"Congratulations to Joe Biden and Kamala Harris on winning the U.S. 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," the Crown Prince wrote.
Ukrainian President Volodymyr Zelensky also congratulated America's newest administration and wrote on Twitter, "Our friendship becomes only stronger!"
Mark Rutte, the Prime Minister of the Netherlands, congratulated America's next leaders and said he hopes to speak to president-elect Biden soon.
"On behalf of the Dutch cabinet I would like to congratulate with their election victory after a close race," Rutte added on Twitter.
President of the Swiss Confederation Simonetta Sommaruga tweeted a picture of Biden and Harris and wrote in English, German and French her congratulations.
"This is a strong signal," Sommaruga wrote, adding that the Swiss and U.S. relationship will "continue to develop and thrive under the new administration."
CNBC's Lauren Feiner contributed to this report.