While Biden’s speech was directed at a global audience — including the more than two dozen heads of state and government who were attending ceremonies in Normandy — it came against the backdrop of a fierce domestic political battle between the president and his predecessor, Donald Trump, who spoke at the D-Day commemorations five years ago.

During his address on the 75th anniversary, Trump hailed the veterans who stormed the beaches of Normandy in 1944 but did not offer similar praise for the global alliances that emerged out of World War II. Biden did not name Trump during his remarks, but he offered an unequivocal endorsement of the global order that the Republican front-runner has trashed, asserting that NATO and other alliances “make us strong.”

“Isolationism was not the answer 80 years ago, and it’s not the answer today,” he said to applause, adding that “the struggle between dictatorship and freedom is unending.”

Biden said his message was particularly relevant given the ongoing war in Ukraine, calling Russian President Vladimir Putin a “tyrant” and pointing out that the NATO alliance has expanded since Russia invaded Ukraine.

“Make no mistake, the autocrats of the world are watching closely to see what happens in Ukraine; to see if we let this illegal aggression go unchecked,” he said. “We cannot let that happen. To surrender to bullies, to bow down to dictators, is simply unthinkable.”

D-Day anniversaries are always celebrated solemnly — but even more so this year, likely to be the last decennial in which some of those who participated in the Normandy landings are alive and well enough to take part.

Biden began his visit to Normandy on Thursday by greeting World War II veterans who participated in the D-Day landings. Most were in wheelchairs. Some are more than 100 years old.

Biden greeted each veteran one by one, offering a salute or handshake and posing for a photograph. “You saved the world,” he said to one. He gave out special challenge coins he had designed for the occasion. He also shared private moments with several veterans, whispering in their ears and congratulating them after French President Emmanuel Macron awarded them the Légion d’Honneur, France’s highest award.

“Here you came to join your efforts with our own soldiers and to make France a free nation,” Macron said. “And you are back here today, at home, if I may say.”

Among those being honored Thursday were Hilbert Margol, 100, of Jacksonville, Fla., a former soldier who helped liberate the Dachau concentration camp, and Roland Martin, 100, of Berkeley, Calif., a former B-17 bomber pilot who was taken captive while on a mission and survived 19 months as a prisoner of war.

In a separate ceremony at the British Normandy Memorial in Ver-sur-Mer, King Charles III echoed a line once spoken by his grandfather, King George VI, by saying that when the Allied forces faced the “supreme test” of D-Day, this “remarkable wartime generation … did not flinch when the moment came.”

Charles, who is receiving treatment for an unspecified form of cancer, wore military dress and spoke in a strong voice from behind a lectern, before participating in a wreath-laying ceremony with Macron.

The main event on Thursday was an international ceremony at Omaha Beach, featuring World War II-era landing craft, parachuters and military flyovers. World leaders paid tribute to the troops who helped carry out the largest naval, air and land assault ever. Despite high casualties, the operation helped establish the U.S. military as the world’s premier fighting force and deepened global alliances that have endured for eight decades.

The celebration of that military triumph was a dramatic contrast from the plodding war in Ukraine, where Russia has been making gains in recent months after more than two years of fighting. The war’s heavy cost has put pressure on politicians in the United States and Europe and at times has strained relations between them.

Putin was not invited to the commemorations, despite the massive casualties the Soviet Union sustained battling Nazi Germany during World War II. Macron acknowledged Soviet sacrifices during his remarks, but in a thinly veiled reference to modern-day Russia, he castigated “those who want to change borders by force or to rewrite history.” Addressing Ukrainian President Volodymyr Zelensky, who was invited, Macron added: “Your presence here today, Mr. President of Ukraine, says it all.”

This is Zelensky’s fourth trip to France since Russia’s 2022 invasion. He has been trying to press his case for additional military support ahead of next week’s Group of Seven summit in Italy, which brings together the world’s wealthiest democracies. Macron on Thursday announced a new commitment to transfer fighter jets to Ukraine and train more Ukrainian soldiers and pilots.

The French president may be hoping this week’s string of high-profile international events — including state visit treatment for Biden this weekend — helps demonstrate the benefits of his global, pro-European vision. That vision is being challenged this week in European Parliament elections. Far-right nationalist factions across the European Union are expected make gains, and in France, the populist National Rally party has been polling far ahead of Macron’s centrist coalition.

Biden has similarly pointed to his administration’s record of building alliances amid the war in Ukraine as a top selling point for his reelection as he seeks to draw a sharp contrast with Trump. In an interview with Time magazine, Biden said Trump “wanted to just abandon” U.S. alliances, and suggested that the former president would ultimately pull the country out of NATO if he returns to the White House.

“The decisions we make in the last couple of years, in the next four years, are going to determine the future of Europe for a long time to come,” Biden said in the May 28 interview. “And so that’s why we can not let NATO fail, we have to build that both politically and economically.”

The president has kept a relatively low profile since arriving in France. He held no public events Wednesday and was a spectator for most of Thursday’s memorial events, speaking briefly to the gathered crowd. But his campaign used the moment to release an ad attacking Trump for his treatment of veterans.

Biden plans to return to Normandy on Friday to give remarks directed at the American people. That speech, the White House said, will focus on “the importance of defending freedom and democracy.” Aides said the president’s remarks will echo themes that are central to his reelection pitch against Trump.

He gave a bit of a preview during his remarks Thursday.

“We’re not far off from the time when the last living voices of those who fought and bled on D-Day will no longer be with us,” he said. “So we have a special obligation. We can’t let what happened here be lost in the silence of the years to come.”

He added: “The fact that they were heroes here that day does not absolve us from what we have to do today. Democracy is never guaranteed. Every generation must preserve it, defend it and fight for it.”

Olorunnipa and Timsit reported from Paris. William Booth in London contributed to this report.