Veterans have gathered by the beaches in the French region of Normandy to mark the 70th anniversary of the D-Day landings that were a turning point in the Allies' defeat of the Nazis in World War Two.

Parachute-landings and fireworks were staged on Thursday, the eve of the anniversary, to honour those who participated in the largest sea assault in military history to confront Nazi Germany's forces.

More than 156,000 troops waded or parachuted onto French soil on June 6, 1944. Nearly 4,500 would be dead by the end of the day.

One of the survivors, Jock Hutton, marked the anniversary by parachuting to the same spot he landed on as an 19-year-old, this time with a member of the British army's Red Devils strapped to his back for safety.

Wearing a bright red jumpsuit, the 89-year-old veteran touched down lightly on the grass just in front of the waiting Prince Charles, dusted himself down briskly and removed his helmet.

"At my age, life tends to get a wee bit boring. So you've got to grab at any chance at excitement," he said.

As colonel-in-chief of the Parachute Regiment, Prince Charles, the heir to the British throne, led the tributes to those in the first wave of air landings shortly after midnight on D-Day.

Wearing a field marshal's uniform, he chatted at length to veterans, most of whom are in their 90s and many of them confined to wheelchairs.

Ukraine shadow

Royals, top brass and about 20 world leaders, including US President Barack Obama and Russia's Vladimir Putin, will attend the main ceremony on Friday.

But while the unity of allies and their bloody sacrifices will be the big theme of the D-Day remembrance, the government leaders will be sounding each other out in private on the worst security challenge in Europe since the Cold War: Ukraine. 

Russia's annexation of Crimea in March and the current standoff in eastern Ukraine between government forces and pro- Russian separatists have driven Russia's relations with the United States and European Union to a post-Cold War low.

French diplomats say French President Francois Hollande hopes to get Putin to at least shake the hand of Ukrainian president-elect Petro Poroshenko on the sidelines of the ceremonies, in what could represent a first step in defusing tensions.  

Putin, who has said he is open to meeting both Obama and Poroshenko while in France, has yet to recognise the legitimacy of the Ukrainian leader who is set to be sworn in on Saturday. 

At a Group of Seven (G7) summit of world leaders in Brussels on Thursday, Hollande called the D-Day tribute "an important occasion to express gratitude and fraternity".

Source: Agencies