France has marked Bastille Day in Paris with a musical military parade on the Champs Elysees avenue, bringing US President Donald Trump's visit to an end while more sombre commemorations took place in Nice.

The Bastille Day celebrations capped two days of Parisian glitz for Mr Trump and his wife Melania, who were French President Emmanuel Macron's guests of honour in commemoration of the 100th anniversary of America's entry into World War I.

The military brass band played a medley of French electronic group Daft Punk's hits in front of the presidents and first ladies.

Pioneers of the 1st Foreign Legion regiment march during the traditional military parade. ( Reuters: Charles Platiau )

Mr Trump spent a large portion of his day and a half in the French capital in the company of Mr Macron, who went to extraordinary lengths to impress the US President by turning a day of national pride into a celebration of American patriotism and friendship between the two countries.

There, US soldiers joined the traditional military parade, a bow to the centennial of the entry of US soldiers into World War I, fighting and dying alongside the French, and to French-US friendship.

Mr Trump and Mr Macron exchanged many handshakes during the course of the US President's first official visit to France, perhaps none more telling than the one they shared after the parade.

As Mr Trump prepared to head home to the United States, the leaders clasped hands and held on to each other as they walked.

The two leaders appeared to set aside their differences in a show of friendship. ( AP: Christophe Archambault (pool) )

Mr Macron, in closing the parade, publicly thanked the US for coming to France's aid during the war, saying "nothing will ever separate us".

"The presence at my side of the President of the United States, Mr Donald Trump, and of his wife, is the sign of a friendship across the ages," Mr Macron said.

Mr Trump made no remarks at the conclusion of the parade, but he returned the kindness in a statement released as Air Force One flew back to the US.

"America and France will never be defeated or divided," Mr Trump said, adding that it was his "high honour" to commemorate, on French soil, France's most France's most historic day.

This year Bastille Day coincided with the 100th anniversary of America's entry into World War I. ( AP: Markus Schreiber )

Remembrance in Nice

As Mr Trump returned home, commemorations followed celebrations for the French President, who travelled to the city of Nice for a solemn remembrance of the lives lost one year ago when a truck sped through revellers celebrating France's national day.

Mr Macron vowed to "fight without mercy" inside and outside France to end extremist attacks like the one last year, which killed 86 revellers in the Riviera city of Nice.

Mr Macron sat with other dignitaries, including Nice's Mayor, Prince Albert II of Monaco and former French presidents, as the names of the victims killed in the July 14, 2016 extremist attack were read out and posted on a board to form the shape of a heart.

French President Emmanuel Macron listened as the names of 86 victims were read out. ( Reuters: Eric Gaillard )

In Nice hundreds gathered to remember victims of the attack, as the city considered the jewel of the Riviera and best known as a centre of carefree urban life tried to move forward without forgetting.

Fireworks displays were banned and the cannon traditionally fired on Bastille Day was silent.

Still, the Patrouille de France air display team streamed the French colours — blue, white and red — over the crowd, hours after flying over the Champs-Elysees to open the Paris Bastille Day parade.

In the Riviera city of Nice people paid respects to the 86 lives lost last year. ( Reuters: Eric Gaillard )

As in Paris, security was tight, the city heavily guarded on land and in the Mediterranean, and the Place Massena, the central square where Mr Macron was to speak, was protected by cement blocks to stop intruders.

"What our attackers want is to simply see us cry, and you responded with dignity," Mr Macron told the crowd.

"We'll respond by a fight without mercy outside and inside our borders against terrorism, everywhere."

Although fireworks were banned, the Patrouille de France air display team flew over Nice. ( Reuters: Eric Gaillard )

Hundreds of people gathered on the famed Promenade des Anglais — where the truck, driven by a Tunisian long-time Nice resident, drove into crowds.

They laid plaques in the national colours that at the day's end will form a 160-metre-long message.

Earlier, the day had begun with a private interfaith gathering with representatives of seven religions.

Nice resident Jean-Paul Collona, 36, said he wanted to be part of the commemoration "because my parents were present during the attack, and their names could simply have been on those plaques".

AP