Joe Biden and Emmanuel Macron have marked the 80th anniversary of D-day with a rallying cry for support for Ukraine as Volodymyr Zelenskiy was embraced by western leaders in Normandy. The US president used his address at the American commemorative event to send a message to Moscow that the US and its allies “will not bow down” and will “stand for freedom”. “To surrender to bullies, to bow down to dictators, is simply unthinkable,” Biden said in a speech at the American cemetery in Normandy. “If we were to do that, it means we’d be forgetting what happened here on these hallowed beaches.” “We will not walk away because if we do Ukraine will be subjugated and it will not end there,” Biden said. “Ukraine’s neighbours will be threatened, all of Europe will be threatened,” he added, describing the Russian president, Vladimir Putin, as a “tyrant bent on domination”. “There are things that are worth fighting and dying for”, Biden said. “Freedom is worth it. Democracy is worth it.” A few hours later, Zelenskiy and his wife, Olena, attended an international event on Omaha beach, where about 2,400 US servicemen lost their lives on 6 June 1944. The couple were met with raucous cheers from the crowds and hugs from fellow leaders. Biden is due to hold a bilateral meeting with Zelenskiy in Paris on Friday. Macron praised Ukraine’s president during his tribute to the courage of those who had fought for freedom, prompting a standing ovation, including by the other 25 heads of state and government. Rishi Sunak, the UK prime minister, was not among them, having chosen not to attend the international commemorative event and return to London for the election campaign. Keir Starmer did attend the international event despite the prime minister’s absence and was seen discussing the latest developments in Ukraine with Zelenskiy. “Thank you to the Ukrainian people for their bravery. We are here and we will not weaken,” Macron said, as guests rose to acknowledge Zelenskiy and French fighter jets roared above in a flypast. “Faced with the return of war on our continent … faced with those who purport to change borders by force to rewrite history, let us be worthy of those who landed here.” “Your presence here today … speaks to all of this,” Macron added, turning to Zelenskiy, who was seated between the Czech president, Petr Pavel, and the European Council president, Charles Michel. Russian representatives had not been invited to the commemorations in Normandy, with French officials claiming that the war in Ukraine made it unthinkable. During a meeting with foreign news outlets in St Petersburg late on Wednesday, Putin dismissed the lack of an invitation, saying “let them celebrate without us”. There were strong signals of support for Ukraine at all the national events and the international service. Embracing one US veteran, Zelenskiy was told: “You’re the saviour of the people.” The Ukrainian leader replied: “No, you saved Europe … You are our hero.” Speaking at the British Normandy memorial at Ver-sur-Mer, which bears the names of the 22,442 servicemen and women under British command who lost their lives on D-day and during the Battle of Normandy in the summer of 1944, King Charles spoke of the need to stand up for freedom. “Again and again across the decades, free nations must stand together to oppose tyranny,” the king said. But it was Biden who made the most direct link between the events of 80 years ago and the invasion of Ukraine. “We must remember that the fact that they were heroes here that day does not absolve us of what we have to do today,” Biden said. “Democracy is never guaranteed. Every generation must preserve it, defend it and fight for it. That’s the test of the ages.” In a clear reference to the “America first” policies of his rival in the race to the White House, Donald Trump, Biden said: “Isolationism was not the answer 80 years ago and is not the answer today.” Trump, who has in recent years backtracked on his threat of taking the US out of Nato, shared his own D-day anniversary message on social media, praising US soldiers as “immortal heroes”. Sunak was deputised at the international commemorative event by the defence secretary, Grant Shapps, prompting criticism from Nigel Farage, the leader of the Reform party. He said: “The prime minister has ducked out of the international D-day event to fly back to the UK to campaign. I am here in Normandy in a personal capacity because I think it matters. Does he?”