The Labour party’s thumping general election victory, which ended 14 years of Conservative party rule in the UK, drew congratulations from leaders around the world – and reminded Keir Starmer of the complex global challenges he will have to navigate as prime minister.

Israel’s president, Isaac Herzog, said he looked forward to cooperating with the new British government as the war in Gaza continues.

“As he prepares to enter Downing Street as prime minister, I look forward to working together with him and his new government to bring our hostages home, to build a better future for the region, and to deepen the close friendship,” he said.

Herzog also expressed his “deepest appreciation and gratitude” to the outgoing prime minister, Rishi Sunak, “for his leadership and for standing with the Israeli people especially during this most difficult period”.

Ukraine’s president, Volodymyr Zelenskiy, congratulated Starmer and said his country and the UK would continue to be “reliable allies through thick and thin”, adding: “We will continue to defend and advance our common values of life, freedom, and a rules-based international order.”

Zelenskiy also made a point of thanking Sunak for helping Ukraine defend itself against Russia.

Kaja Kallas, the prime minister of Estonia and who is poised to become the EU’s top diplomat, sent a message stressing the importance of “common security” – an allusion to the growing fears prompted by Russia’s invasion of Ukraine.

“Congratulations on your historic election victory@Keir Starmer,” Kallas wrote on X. “Estonia and the UK are the strongest of allies and the closest of friends. The UK’s commitment to our common security is valued by every Estonian.”

The European Council president, Charles Michel, congratulated Starmer on his triumph, which came just over eight years after the UK voted to leave the EU.

“The EU and the UK are crucial partners, cooperating in all areas of mutual interest for our citizens,” he wrote on X. “I look forward to working with you and your government in this new cycle for the UK.” Michel said the shared challenges ahead included stability, security, energy and migration.

Emmanuel Macron – who faces his own day of reckoning on Sunday as France heads to the polls for the second round of the snap legislative elections on which he has gambled his political future – said he and Starmer would “continue the work begun with the UK for our bilateral cooperation, for peace and security in Europe, for the climate and for AI”.

The Irish taioseach, Simon Harris, also took the opportunity to stress the importance of his country’s relationship with its neighbour.

“I look forward to working with you as close neighbours and friends,” he said. “The relationship between Ireland and the UK is deep and consequential. I look forward to it going from strength to strength.”

Narendra Modi, who last month won a third term as India’s prime minister, offered Starmer his “heartiest congratulations and best wishes”, while Canada’s prime minister, Justin Trudeau, congratulated the new PM on a “historic victory” and urged him to roll up his sleeves.

“Lots of work ahead to build a more progressive, fair future for people on both sides of the Atlantic,” he said. “Let’s get to it, my friend.”

The Australian prime minister, Anthony Albanese, said: “Congratulations to my friend and new UK prime minister on his resounding election victory – I look forward to working constructively with the incoming government.”

New Zealand’s prime minister, Christopher Luxon, said he was looking forward to “working on every opportunity together as prime ministers” and thanked Sunak for his “service to your nation and friendship to New Zealand”.

The election of a centre-left leader goes against the tide of recent European elections, in which the far right has made huge strides.

In last month’s European parliament elections, populist parties made significant gains in countries including Italy, France, Austria, Hungary and Germany, where Olaf Scholz’s Socialist Democratic party slid to its worst result in a national election.

In France, Emmanuel Macron called snap elections after his centrist alliance was trounced in the poll; Marine Le Pen’s National Rally is now on the cusp of becoming the biggest parliamentary party and potentially forming France’s first far-right government after gaining the most votes in the first round of the national election.

Thursday’s election in the UK also comes four months before Americans go to the polls to choose between Joe Biden and Donald Trump.

Starmer’s victory also led many international headlines on Friday morning. The New York Times offered a straight appraisal of the results, “Labour party wins UK election in a landslide”, but noted both Starmer’s “remarkable turnaround” of his party and the fact that Nigel Farage, “a supporter of Donald Trump and a driving force behind Brexit”, had won a seat.

Germany’s Die Welt offered a pithy precis – “Tories experience ‘massacre’, Labour have clear victory; ‘Mr. Brexit’ returns” – while France’s Le Monde said Labour’s “historic victory” was evidence of “the thorough reconstruction of the British political landscape”.

In Spain, where the far-right Vox is the third biggest party in parliament, La Vanguardia noted the strong showing by Farage’s Reform UK party: “Labour storms it while the far right makes spectacular gains in the UK.”

And, in an introduction to its Friday podcast, the online Spanish newspaper ElDiario was blunt in its appraisal of the state of the UK – and of Starmer’s Tory predecessors: “A country where nothing works like it used to, a historical power now full of cracks, a society that has fallen victim to its own decisions has voted for change after 14 years of Conservative rule, and for a progressive leader from a humble background without eccentricities.”