“We cannot let what happened here be lost in the silence of the years to come,” Biden said. “The fact that they were heroes here that day does not absolve us of what we have do today.”

Biden’s speech was a combination of somber reflections and calls for action. Standing alongside French President Emmanuel Macron, Defense Secretary Lloyd Austin and dozens of American veterans, Biden lauded the courage of World War II’s last living veterans while connecting their fight eight decades ago to the ongoing conflict in Ukraine.

Noting that Ukranians who have fought invading Russian troops for the past two years, Biden touted the recent expansion of NATO and vowed never to back down to autocrats like Russian President Vladimir Putin.

The coalition of countries backing Ukraine “will not walk away,” Biden promised, warning that “all of Europe will be threatened” should Ukraine fall. “The autocrats of the world are watching closely … to surrender to bullies, to bow down to dictators, is simply unthinkable.”

The remarks marked the first public leg of a multi-day trip in which Biden is expected to commemorate the anniversary of one of the most significant military battles in U.S. history and to restate the case of democratic values.

Biden arrived at the Normandy American Cemetery more than two hours before the ceremony was slated to begin. And after recording an interview with ABC News anchor David Muir, he met privately with 41 of the D-Day veterans, a majority of them 100 years old or older, who were attending the event. The president, alongside first lady Jill Biden, met veterans one-by-one while in a small glass-backed gazebo, which looked out on Omaha Beach. Biden saluted and shook hands with all before posing for pictures.

“The greatest generation ever man,” he remarked to one veteran, who told the president he was 102. “You saved the world,” he said to another, bending down to look into his eyes from close range.

As proceedings got underway, all of the approximately 170 American WWII veterans were brought in on wheelchairs, underscoring both the distance that has passed from D-Day and the likelihood that this commemoration will be the last big one with any real presence of living veterans from that war.

Macron, who spoke before Biden during the ceremony, described the “eternal bond” between the U.S. and France. “It’s a blood tie, shed for liberty,” he said, noting that each soldier who landed on the beaches of Normandy left families, loved ones, hopes and dreams behind. France’s president, as Biden would, addressed several of the veterans on stage by name, briefly recounting their history of service prior to D-Day and after. “The free world needed each of you and you said yes when we asked for help,” he said in French before switching to English. “And you are back here today at home.”

Biden is set to attend a second, larger D-Day commemoration at Omaha Beach Thursday afternoon with a number of other world leaders, including Macron, British Prime Minister Rishi Sunak, German Chancellor Olaf Scholz, Canadian Prime Minister Justin Trudeau and Netherlands Prime Minister Mark Rutte, who is likely to be NATO’s next secretary general.

Ukrainian President Volodymyr Zelenskyy will also be among the guests. Biden and Zelenskyy are likely to meet briefly following the event where they are expected to briefly discuss the latest developments around Russia’s invasion and additional security guarantees and actions the U.S. and other allies may be able to take.

Biden will return to Normandy on Friday for a longer speech he plans to deliver at Pointe du Hoc, the legendary 100-foot cliff that Army rangers scaled during the D-Day invasion. The back-to-back speeches over two days here, according to national security adviser Jake Sullivan, are about “drawing a through line” from World War II through the Cold War to the present day.

“The Pointe du Hoc speech is a speech about, in his view, timeless principles — principles that have served as the foundation of American security and American democracy for generations — including the generation that scaled those cliffs, including today’s generation, including the next generation,” Sullivan told reporters Tuesday evening aboard Air Force One.