Cannon shots have been fired across the Seine as Emmanuel Macron was inaugurated as France's new president at the Elysee palace in Paris on Sunday. Immediately, he launched into his mission to fight terrorism and shake up French politics and the EU.

At 39, Macron is the youngest president in the country's history and the 8th president of France's Fifth Republic, which was created in 1958.

A former economy minister with pro-business, pro-European views, he is the first French president who does not originate from one of the country's two mainstream parties.

Mr Macron takes charge of a nation that, when Britain leaves the European Union in 2019, will become the EU's only member with nuclear weapons and a permanent seat on the UN Security Council.

He met for an hour with his predecessor, Francois Hollande, in the president's office, taking a last few minutes to discuss the most sensitive issues facing France, including the country's nuclear codes.

In a visibly moving moment for both, Mr Macron accompanied Mr Hollande to his car, shaking hands and applauding him along with the employees of the French presidency who gathered in the palace's courtyard.

The two men had known each other well. Mr Macron was Mr Hollande's former adviser, then his economy minister from 2014 to 2016, when Mr Macron quit the Socialist government to launch his own independent presidential bid.

In his inauguration speech, Mr Macron said he will do everything that is necessary to fight terrorism and authoritarianism and to resolve the world's migration crisis.

He also listed "the excesses of capitalism in the world" and climate change among his future challenges.

"We will take all our responsibilities to provide, every time it's needed, a relevant response to big contemporary crises," He said.

Mr Macron announced his determination to push ahead with reforms to free up France's economy and pledged to press for a "more efficient, more democratic" EU.

France is a founding member of the 28-nation bloc, which Britain plans to leave in 2019, and its third-largest economy after Germany and Britain.

About 300 guests, officials and family members gathered in the Elysee reception hall, including Mr Macron's wife, Brigitte, wearing a lavender blue dress by French designer Nicolas Ghesquiere for Louis Vuitton.

The new first lady briefly posed for photographers with her husband at the front porch of the palace after Mr Hollande left. The couple will now live at the Elysee palace.

Outside the Elysee, a few dozen supporters waved French tricolor and European blue flags at the arrival of the new president.

Following the ceremony and military honours at the Elysee palace, Mr Macron was to go to the Tomb of the Unknown soldier, at the Arc de Triomphe at the top of the Champs-Elysees Avenue, a tradition followed by all heads of states in France's modern history.

He will also meet with Paris Mayor Anne Hidalgo later Sunday.

His first visit abroad will be to Germany on Monday, to visit with German Chancellor Angela Merkel in Berlin and then in the following days will have to name his prime minister and form a government.

He has promised to reinvigorate French politics by bringing in new faces. His Republic on the Move movement has announced an initial list of 428 candidates for the 577 seats up for grabs in France's lower house of parliament in June.

Mr Macron is seeking a majority of lawmakers so he can pass his programs.

Many of the Republic on the Move candidates are newcomers in politics. Their average age is 46, compared to 60 for the outgoing assembly. Half of them are women. Only 24 are lawmakers running for re-election, all Socialists.

Mr Hollande described the "terrible ordeals" that marked his five-year term, from deadly attacks to Greece's debt crisis, and defended his unpopular presidency in a series of tweets minutes after leaving the Elysee Palace.

He noted his accomplishments in getting the Paris Agreement on climate change, legalising gay marriage and doing "everything possible to ensure that Greece stays in Europe".

"We lived through crises but we held together. France remained France," he tweeted.

After the inauguration, 21 cannon shots were fired from across the Seine River at the Invalides monument, where Napoleon is entombed.

Mr Macron then walked alone across the cobblestones of the Champs-Elysees avenue to the Arc de Triomphe, where he lay a wreath and re-ignited the flame at the Tomb of the Unknown Soldier.

He waved to supporters taking selfies and greeted veterans and military officers in formation beneath the arch.