Originally Published: 07 NOV 20 12:50 ET

Updated: 07 NOV 20 23:36 ET

By Zamira Rahim and Martin Goillandeau, CNN

(CNN) -- A stream of world leaders congratulated President-elect Joe Biden and Vice President-elect Kamala Harris on their victory in the 2020 US presidential election on Saturday, with many striking a jubilant tone on social media.

Canadian leader Justin Trudeau emphasized the close alliance between Canada and the US in his remarks.

"Congratulations Joe Biden and Kamala Harris," Trudeau wrote on Twitter. "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 Europe, the reactions were led by Irish politicians. "I want to congratulate the new President Elect of the USA [Joe Biden]," Irish Prime Minister Micheál Martin tweeted after the result emerged. Martin also referenced Biden's Irish-American heritage, adding: "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!"

Ireland's health minister Simon Coveney said the country's government looked "forward to working with a (Biden/Harris) presidency to sustain & strengthen Irish American relations, and so much more."

The leaders of US allies South Korea and Australia also congratulated Biden and Harris.

Australian Prime Minister Scott Morrison said in a statement that "the President-elect has been a great friend of Australia over many years," and noted that Biden will step into the role at a crucial time as the world battles the Covid-19 pandemic.

"American leadership is indispensable to meeting these challenges and upholding the rules, norms and standards of our international community," Morrison said.

Morrison thanked current US President Donald Trump Vice President Mike Pence and Secretary of State Mike Pompeo for their work with Australia over the past four years.

South Korean President Moon Jae-in tweeted he looked forward to working with Biden and Harris.

"Our alliance is strong and the bond between our two countries is rock-solid," Moon said.

'Welcome back America!'

In France Paris Mayor Anne Hidalgo also reacted on Twitter, declaring "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," she wrote.

The US left the landmark agreement earlier this week.

French President Emmanuel Macron also posted a lively tweet, writing: "The Americans have chosen their President.We have a lot to do to overcome today's challenges. Let's work together!

The sense of Biden's election strengthening the US global role was also echoed in other European statements.

Norbert Röttgen, Chairman of the German Foreign Affairs Committee, said he was "very happy for all my American friends and for this great chance to revive our transatlantic friendship," while Foreign Minister Heiko Maas said Germany wanted "to invest in our cooperation for a new transatlantic beginning, a new deal."

London mayor Sadiq Khan said Biden and Harris' win meant it was "time to get back to building bridges, not walls" in a dig at President Trump's policy of building a wall at the US-Mexico border.

Khan and Trump have clashed repeatedly over the years.

UK Prime Minister Boris Johnson also congratulated Biden and Harris and stressed the importance of the transatlantic relationship.

"Congratulations to Joe Biden on his election as President of the United States and to Kamala Harris on her historic achievement," Johnson said on Twitter.

"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."

Johnson and Trump's administrations were thought to be close allies and UK Foreign Secretary Dominic Raab took care to acknowledge White House incumbent.

"It was a close contest and [Donald Trump] fought hard," he wrote on Twitter.

'Critical shared interests'

Some politicians who had closer ties to Trump were more muted in their congratulations and took the time to reflect on the sitting president's achievements.

In Israel, Prime Minister Benjamin Netanyahu is yet to react but a host of politicians from the country congratulated Biden and Harris.

Netanyahu has worked closely with the White House on Middle East policy in recent years.

"Congratulations to my friend President-Elect Joe Biden and Vice President-Elect Kamala Harris. The relationship between our countries is based on deeply held values and critical shared interests which I know will be at the heart of your administration," Israeli Opposition leader Yair Lapid said.

Amir Peretz, leader of the Labor Party, and a minister in Netanyahu's coalition government also struck a diplomatic tone.

"I congratulate the election of President Joe Biden and wish him success," Peretz wrote on Twitter Saturday.

"I thank [President] Trump for bringing achievements as a friend of Israel like the peace agreements. The United States has once again proved that democracy is the bedrock of the state's existence."

'The ugly face of liberal democracy'

World leaders spent the past week watching closely as the election results gradually unfolded. Some, like UK Prime Minister Johnson, tread lightly in anticipation of an unclear outcome. Canadian Prime Minister Trudeau had said he was observing cautiously so as to not interfere with the process. Others cheered on the prospect of a Biden win. Paris Mayor Hidalgo had voiced her ongoing support for Biden and hope for renewed partnerships with the US on issues like climate change.

Many foreign onlookers had concerns about President Trump's comments on voter fraud and early claims of victory, and the impact those might have on democracy globally. A senior German politician described Trump's approach to the ongoing vote-counting as "unbelievable" and "awful behavior."

Russia's Foreign Ministry had commented on Twitter that the tight race was a sign of weakness in the US electoral system.

Iran's Supreme Leader Ayatollah Ali Khamenei, whose relationship with Washington has soured under Trump, echoed the sentiment after Saturday's election outcome. "The situation in the US and what they themselves say about their elections is a spectacle!" Khamenei said on Twitter.

Kamala Harris' historic night

The significance of Harris' victory as Vice-President elect was not lost on the world stage. The election call on Saturday made Harris the first woman to win the vice presidency, not to mention the first Black woman and the first South Asian woman to achieve this.

Indian prime minister Narendra Modi offered Harris, the daughter of an Indian mother and Jamaican father, his "heartiest congratulations" on Twitter.

"Your success is pathbreaking, and a matter of immense pride not just for your chittis, but also for all Indian-Americans," Modi wrote.

"Chitti" is a Tamil word used to refer to the younger sisters of a person's mother.

The Indian leader is a close Trump ally but said he was confident that "the vibrant India-US ties will get even stronger" with Harris' support.

German Chancellor Angela Merkel, Belgian Prime Minister Alexander De Croo and Indian opposition figure Rahul Gandhi were among those to congratulate Harris on her groundbreaking achievement.

In Colombia, mayor of Bogota Claudia Lopez had a particularly exuberant reaction on Twitter.

"How proud that a woman, Afro, Indian, Jamaican, great professional and extraordinary leader, became the Vice Presidency of the United States for the first time!" Lopez wrote.

"With every woman who wins, we all win!"