Germany, Canada and France, which have had strained ties with the Trump administration despite being its G7 and NATO partners, were among the first to recognize Biden's victory, soon after major US television networks declared it.

"I look forward to future cooperation with President Biden," German Chancellor Angela Merkel said in a statement on Twitter. "Our transatlantic friendship is irreplaceable if we are to master the great challenges of our time."

Merkel's finance minister, Olaf Scholz, went further, suggesting a Biden administration could mark a reset of trans-Atlantic ties.

Canadian Prime Minister Justin Trudeau said he looked forward to tackling "the world's greatest challenges" with the new administration, including climate change, an issue with which many nations have argued over with Trump.

British Prime Minister Boris Johnson, who has had a much smoother relationship with Trump, also picked up the theme of climate change in congratulating Biden.

"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."

Washington formally quit the Paris accord on limiting greenhouse gas emissions on Wednesday, fulfilling a pledge by Trump to withdraw the world's second-largest emitter from the pact. Biden has promised to rejoin the agreement if elected.

"The Americans have chosen their President," French President Emmanuel Macron tweeted. "We have a lot to do to overcome today's challenges. Let's work together!"

Many leaders did not mention Trump, but Spain's far-left deputy prime minister, Pablo Iglesias, said his departure as president would leave the far right weakened around the world.

"Trump is confirmed to have lost the election. This is good news for the planet, as the global far right loses its most powerful political asset," Iglesias tweeted.

Ireland, where Biden traces his family roots, called him the 46th US President, despite Trump accusing Biden of "rushing to falsely pose as the winner." Trump has complained of electoral fraud without providing evidence.

"Ireland takes pride in Joe Biden's election, just as we are proud of all the generations of Irish women and Irish men and their ancestors whose toil and genius have enriched the diversity that powers America," Prime Minister Micheal Martin said in a statement.

Indian Prime Minister Narendra Modi singled out Biden's running mate, Kamala Harris, in his congratulatory tweet. Harris, whose mother emigrated from India, becomes the first woman, first Black American and first Asian American to win the second highest US office of Vice-President.

"Your success is path-breaking and a matter of immense pride not just for your chittis, but also for all Indian-Americans," Modi wrote, using the Tamil word for "aunts" which Harris had used when she accepted the Democratic Party's VP nomination.

Egypt, one of Washington's biggest allies in the Middle East, also congratulated Biden, as did Lebanon, which has had fraught relations with the United States.

On Friday, the Trump administration imposed sanctions on Gebran Bassil, the leader of Lebanon's biggest Christian political bloc and son-in-law of President Michel Aoun, accusing him of corruption and ties to armed Shi'ite group Hezbollah.

Aoun said on Twitter that he hoped the balance in Lebanese-American relations would return under a Biden administration.

Some nations with closer ties to Trump were quiet on Saturday night or reluctant to proclaim Biden as president-elect, though Australian Prime Minister Scott Morrison paid thanks to Trump at the end of his congratulations to Biden.

Polish President Andrzej Duda congratulated Biden on running "a successful presidential campaign" and said Poland would maintain a high-quality strategic partnership with Washington as "we await the nomination by the Electoral College".

Russia, though, gave no immediate comment. US intelligence officials accuse the Kremlin of intervening in the 2016 campaign to help Trump get elected - allegations that it denies.

In the run-up to the vote, President Vladimir Putin seemed to hedge his bets, frowning on Biden's anti-Russian rhetoric but welcoming his comments on nuclear arms control. Putin also defended Biden's son, Hunter, against criticism from Trump.

Israeli and Saudi governments, whose leaders are among the closest Trump allies in the Middle East, were also quiet - as was Hungary's Viktor Orban, who had endorsed Trump's re-election bid and accused Biden's Democrats of "moral imperialism".

Israeli Prime Minister Benjamin Netanyahu made no immediate comment, and a picture of him and Trump remained at the top of the hawkish Israeli leader's Facebook page.

Pakistan's Prime Minister Imran Khan said he looked forward to work with Biden on seeking peace in neighboring Afghanistan.

The Trump administration has been drawing down US troops from Afghanistan in a deal with Taliban insurgents, which Kabul and its allies have long regarded as backed by Pakistan.