PARIS (AFP, Reuters) - Emmanuel Macron said France had chosen "hope" as he was officially inaugurated as the country's youngest president ever on Sunday (May 14) in a sumptuous inauguration ceremony in the Elysee Palace presidential residence in Paris following his May 7 election victory.

Macron, 39, promised in his first speech as president that the beleaguered European Union would be "reformed and relaunched" during his time in office.

On arriving for the ceremony at the 18th century palace, the former investment banker and economy minister held a private meeting with outgoing Socialist President Francois Hollande on state affairs which included the transfer of access to France's nuclear missile launch codes.

Macron becomes France's youngest post-war leader and the first to be born after 1958 when President Charles de Gaulle put in place the Fifth Republic.

He officially became president when Laurent Fabius, chairman of the constitutional council and a former prime minister, read out the results of the election in which Macron beat far right leader Marine Le Pen.

Witnessing the ceremony were Macron's wife, his 64-year-old former school teacher Brigitte, her two daughters and their families.

The former drama teacher's romance with the new president, and their 25-year age gap, has already generated media interest around the world.

After a formal lunch, Macron will visit the Arc de Triomphe, a war memorial at the top of the Champs Elysees avenue, and will later make a stop at the Paris town hall.

Security was tight with around 1,500 police officers deployed near the presidential palace and the nearby Champs Elysees avenue and surrounding roads will be blocked off.

PM named, then Berlin

Amid applause from onlookers, Macron accompanied Hollande to his vehicle in the forecourt of the Elysee Palace and then waved goodbye to his former mentor as he was driven out into the streets of Paris.

Hollande is clearly delighted at the election of the former investment banker, who scored a clear victory over far-right candidate Marine Le Pen on May 7.

The current president launched Macron's political career, plucking him from the world of investment banking to be an advisor and then his economy minister.

"I am not handing over power to a political opponent, it's far simpler," Hollande said on Thursday.

On Monday, Macron is expected to reveal the closely-guarded name of his prime minister, before flying to Berlin to meet German Chancellor Angela Merkel.

It is virtually a rite of passage for French leaders to make their first European trip to meet the leader of the other half of the so-called "motor" of the EU.

Pro-EU Macron wants to push for closer cooperation to help the bloc overcome the imminent departure of Britain, another of its most powerful members.

He intends to press for the creation of a parliament and budget for the eurozone.

Merkel welcomed Macron's decisive 32-point victory over Le Pen, saying he carried "the hopes of millions of French people and also many in Germany and across Europe".

In June, Macron faces what the French media are calling a "third round of the presidential election" when the country elects a new parliament in a two-round vote.

The new president needs an outright majority to be able to enact his ambitious reform agenda.

The year-old political movement "Republique en Marche" (Republic on the Move, REM) that he formed to launch his presidential bid intends to field candidates in virtually every constituency in the country.

It unveiled 428 of its 577 candidates this week, saying it wants to bring fresh faces into the National Assembly lower house of parliament.

Half of them have never held elected office, including a retired female bullfighter and a star mathematician, and half of them are women.

Host of new faces

Macron met many of the candidates gathered at a Paris museum on Saturday and told them they had an "immense responsibility".

"You are the new faces of French politics," some of those present quoted him as saying.

Macron won one of the most unpredictable French elections in modern history marked by scandal, repeated surprises and a last-minute hacking attack on his campaign.

Just as campaigning ended, hundreds of thousands of emails and documents stolen from his campaign were dumped online, leading Macron to call it an attempt at "democratic destabilisation".

US authorities have said they believe Russian hackers were behind the attack.

The election saw voters reject France's two traditional political forces of left and right. Their candidates were eliminated in the first round.

Unpopular Hollande was the first to bow to the rebellious mood in December as he became the first sitting president not to seek re-election in the French fifth republic, founded in 1958.