As Allied nations marked 80 years since the D-Day landings that began the liberation of France from Nazi German occupation, Supreme Allied Commander Europe Cavoli's eyes were turned to the Russian invasion of Ukraine and Moscow's potential future threat to NATO countries.

NATO "is ready to do collective territorial defence", Cavoli said in Normandy.

He pointed to a vast exercise dubbed Steadfast Defender 24, which involved 90,000 NATO troops across multiple European countries from January to May.

"We've shifted our focus entirely over the last couple of years. We used to do out-of-area operations, now we're focused on defending the territory of the alliance," Cavoli said.

But "when it comes to military equipment... we need to build more, we need to expand our industrial base," he added.

Russia's invasion of Ukraine and Kyiv's Western-backed defence have shown the vast appetite of modern conflicts for ammunition and other equipment.

It has, however, taken time for defence manufacturers to ramp up output of items from artillery shells to vehicles and drones.

"We need to generate hardware more quickly. I think all the nations in the alliance realise that and are working on it," Cavoli said.

- 'Study everything' -

He joked that "if you ever want to feel a little bit of pressure, take a job Dwight D. Eisenhower had" -- referring to the World War II commander and later US president who was the first to hold the position Cavoli took up in 2022.

Facing a new generation of warfare, the general added that NATO is "going to take a very deliberate effort to study everything about the (Russia-Ukraine) conflict so that we can develop from it".

He cited "innovative uses of hardware", such as the low-cost drones used by both sides for reconnaissance and attack.

NATO troops would also be learning from "techniques and tactics" used on Ukrainian battlefields at a new "lessons learned" centre to be set up in Poland, Cavoli added.

Speaking at the cemetery for Americans killed in the D-Day landings and subsequent fighting through Normandy 80 years ago, Cavoli said that "these cemeteries thoughout Europe, throughout the world, are very inspirational to us.

"They remind me of my own soldiers that I've lost," he added.

Beyond turning out more weaponry, "there's a difference between having the equipment and really being able to use it effectively... it's our soldiers, our airmen, our marines, our sailors who are true experts.

"The professionalism is what makes us have an advantage," Cavoli said.

France's enduring memory of the liberation from Nazi German occupation was on display throughout the landing zone, with many houses along the roads to the cemetery flying the flags of the United States and other Allied nations.

The cemetery and the warm local welcome for US troops are "just a living example of US-French friendship and also the way an alliance comes together and not only fights a war, but stays together after a war," Cavoli said.