COLLEVILLE-SUR-MER, France (AP) — President Joe Biden marked the 80th anniversary of D-Day on Thursday by pledging “we will not walk away” from the defense of Ukraine and allow Russia to threaten more of Europe.

“To surrender to bullies, to bow down to dictators, is simply unthinkable,” he said during a ceremony 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."

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President Joe Biden and first lady Jill Biden walk in the Normandy American Cemetery following a ceremony to mark the 80th anniversary of D-Day, Thursday, June 6, 2024, in Normandy. (AP Photo/Evan Vucci)

President Joe Biden and first lady Jill Biden walk in the Normandy American Cemetery following a ceremony to mark the 80th anniversary of D-Day, Thursday, June 6, 2024, in Normandy. (AP Photo/Evan Vucci)

President Joe Biden and first lady Jill Biden stand before a wreath at the Normandy American Cemetery following a ceremony to mark the 80th anniversary of D-Day, Thursday, June 6, 2024, in Normandy. (AP Photo/Evan Vucci)

THE GRAVE SHOWN MAY NOT BE PRIVATE FIRST CLASS JOHN GREENFIELD'S GRAVE - President Joe Biden and first lady Jill Biden, visit the graves at the Normandy American Cemetery after a ceremony to mark the 80th anniversary of D-Day, Thursday, June 6, 2024, in Normandy. (AP Photo/Evan Vucci)

President Joe Biden speaks with World War II veteran Bob Pedigo after French President Emmanuel Macron honored Pedigo with the Legion of Honor medal, during a ceremony to mark the 80th anniversary of D-Day, Thursday, June 6, 2024, in Normandy. (AP Photo/Evan Vucci)

President Joe Biden speaks with War II veteran Victor Charey after French President Emmanuel Macron honored Carey with the Legion of Honor medal, during a ceremony to mark the 80th anniversary of D-Day, Thursday, June 6, 2024, in Normandy. (AP Photo/Evan Vucci)

President Joe Biden delivers a speech during a commemorative ceremony to mark D-Day 80th anniversary, Thursday, June 6, 2024 at the US cemetery in Colleville-sur-Mer, Normandy. Normandy is hosting various events to officially commemorate the 80th anniversary of the D-Day landings that took place on June 6, 1944. (AP Photo/Daniel Cole, Pool)

President Joe Biden and First Lady Jill Biden leave after a commemorative ceremony to mark D-Day 80th anniversary, Thursday, June 6, 2024 at the US cemetery in Colleville-sur-Mer, Normandy. Normandy is hosting various events to officially commemorate the 80th anniversary of the D-Day landings that took place on June 6, 1944. (AP Photo/Daniel Cole, Pool)

President Joe Biden and first lady Jill Biden, greet a World War II veteran during ceremonies to mark the 80th anniversary of D-Day, Thursday, June 6, 2024, in Normandy. (AP Photo/Evan Vucci)

President Joe Biden greets World War II veteran Richard Stewart after he was awarded in the Legion of Honor by French President Emmanuel Macron during a ceremony to mark the 80th anniversary of D-Day at the Normandy American Cemetery in Colleville-sur-Mer, Normandy, France, Thursday, June 6, 2024. World leaders are gathered Thursday in France to mark the 80th anniversary of the D-Day landings. (AP Photo/Virginia Mayo)

President Joe Biden speaks with World War II veteran Bob Pedigo after French President Emmanuel Macron honored Pedigo with the Legion of Honor medal, during a ceremony to mark the 80th anniversary of D-Day, Thursday, June 6, 2024, in Normandy. (AP Photo/Evan Vucci)

French President Emmanuel Macron, 2nd left, his wife Brigitte Macron, left, and US President Joe Biden, center right, and first lady Jill Biden attend a ceremony together with World War II veterans at an US cemetery near Colleville-sur-Mer Normandy, Thursday, June 6, 2024. World War II veterans from across the United States as well as Britain and Canada are in Normandy this week to mark 80 years since the D-Day landings that helped lead to Hitler's defeat. (AP Photo/Laurent Cipriani)

President Joe Biden and French President Emmanuel Macron are shown on a large screen greeting a World War II veteran during ceremonies to mark the 80th anniversary of D-Day, Thursday, June 6, 2024, in Normandy. (AP Photo/Evan Vucci)

President Joe Biden, first lady Jill Biden, French President Emmanuel Macron, his wife Brigitte Macron, walk on stage during ceremonies to mark the 80th anniversary of D-Day, Thursday, June 6, 2024, in Normandy. (AP Photo/Evan Vucci)

President Joe Biden and first lady Jill Biden, greet a World War II veteran during ceremonies to mark the 80th anniversary of D-Day, Thursday, June 6, 2024, in Normandy. (AP Photo/Evan Vucci)

President Joe Biden and first lady Jill Biden, greet a World War II veteran during ceremonies to mark the 80th anniversary of D-Day, Thursday, June 6, 2024, in Normandy. (AP Photo/Evan Vucci)

President Joe Biden and first lady Jill Biden, greet a World War II veteran during ceremonies to mark the 80th anniversary of D-Day, Thursday, June 6, 2024, in Normandy. (AP Photo/Evan Vucci)

President Joe Biden and first lady Jill Biden, greet a World War II veteran during ceremonies to mark the 80th anniversary of D-Day, Thursday, June 6, 2024, in Normandy. (AP Photo/Evan Vucci)

U.S. President Joe Biden, center second right, first lady Jill Biden, center right, French President Emmanuel Macron, center second left, and his wife Brigitte Macron, center left, and American WWII veterans attend a ceremony to mark the 80th anniversary of D-Day at the Normandy American Cemetery in Colleville-sur-Mer, Normandy, France, Thursday, June 6, 2024. World leaders are gathered Thursday in France to mark the 80th anniversary of the D-Day landings. (AP Photo/Virginia Mayo)

President Joe Biden greets WW II veteran Richard Stewart after he was awarded in the Legion of Honor by French President Emmanuel Macron, during a commemorative ceremony to mark D-Day 80th anniversary, Thursday, June 6, 2024 at the US cemetery in Colleville-sur-Mer, Normandy. Normandy is hosting various events to officially commemorate the 80th anniversary of the D-Day landings that took place on June 6, 1944. (AP Photo/Daniel Cole, Pool)