Francois Hollande is set to be sworn in as French president, before travelling to Berlin to discuss the future of the eurozone with Chancellor Angela Merkel.
He will be the first Socialist leader since 1995 to occupy the Elysee Palace.
Francois Hollande will later try to “find a compromise” with Angela Merkel over the German-led focus on austerity as the way out of Europe’s economic crisis.
On Monday, the value of stock markets and the euro fell amid continuing political uncertainty in Greece.
The chairman of the eurozone finance ministers, Jean-Claude Juncker, insisted on Monday night that they would do “everything possible” to keep Greece in the euro.
Jean-Claude Juncker said he looked forward to the swift formation of a new Greek government, nine days after the general election.
But he also warned that Greece had to continue the “significant efforts” already made to restructure its economy despite these policies having been rejected by a majority of voters.
Francois Hollande is expected to be sworn in shortly after meeting outgoing President Nicolas Sarkozy at the Elysee Palace in central Paris at around 10:00.
The new leader has asked that the inauguration ceremony be kept as low-key as possible, and has invited just three dozen or so personal guests to join the 350 officials attending. Neither Francois Hollande’s children nor those of his partner, Valerie Trierweiler, will be there.
The ceremony will be followed by the traditional procession in an open-topped car along the Avenue des Champs-Elysees and the laying of the wreath at the Tomb of the Unknown Soldier underneath the Arc de Triomphe.
Francois Hollande will then pay tribute to the 19th-Century educational reformer Jules Ferry and the Nobel Prize-winning chemist Marie Curie.
Francois Hollande is set to be sworn in as French president, before travelling to Berlin to discuss the future of the eurozone with Chancellor Angela Merkel
His first lunch as president will be with the former Socialist prime ministers Pierre Mauroy, Laurent Fabius, Michel Rocard, Edith Cresson and Lionel Jospin.
Francois Hollande, 57, has spent the past week preparing to take up the presidency, and now the work begins in earnest.
His first job is to name a new prime minister, who our correspondent says will most likely be Jean-Marc Ayrault, leader of the Socialist group in parliament, a German speaker and a close ally.
Michel Sapin, a key economic adviser to Francois Hollande, is tipped to be finance minister.
On Tuesday afternoon, Francois Hollande will fly to Germany for dinner with Chancellor Angela Merkel, who says she will welcome the new leader “with open arms”.
But her embrace will hide some embarrassment after Angel Merkel openly supported Nicolas Sarkozy in the election battle.
“We don’t think the same on everything,” Francois Hollande acknowledged on French television on Monday.
“We’ll tell each other that so that together we can reach good compromises.”
Francois Hollande has demanded that a European fiscal pact that cracked down on overspending be renegotiated to include a greater emphasis on measures to stimulate growth, while Germany insists the treaty must be respected.
Whatever their differences, the crisis in the eurozone will put them under huge pressure to compromise, our correspondent says.
As the eurozone’s two biggest economies – and biggest contributors to its bailout funds – Germany and France are key decision-makers over the strategy supposed to pull Europe out of crisis.
According to official figures released on Tuesday morning, the French economy showed no growth in the first quarter of 2012. Growth in the final quarter of 2011 was also revised down to 0.1% from 0.2%.
However, Germany’s economy grew by a stronger than expected 0.5% in the first three months of the year.
Following his German trip, Francois Hollande will hold his first cabinet meeting on Thursday followed by a visit to Washington to meet US President Barack Obama on Friday.
• 08:00-08:30 Francois Hollande arrives at the Elysee Palace and meets Nicolas Sarkozy
• 08:30-09:30 Inauguration ceremony followed by procession up the Champs-Elysees
• 09:45 Francois Hollande lays a wreath at the Tomb of the Unknown Soldier, under the Arc de Triomphe
• 11:45 Francois Hollande pays tribute to Jules Ferry in the Jardin des Tuileries
• 12:30 Francois Hollande honours Marie Curie at the Curie Institute
• 13:00 Ceremony at the Hotel de Ville with Paris mayor Bertrand Delanoe
Ukraine denounces a threatened EU boycott of next month’s Euro 2012 football championship as “destructive”.
In a statement, Ukraine’s foreign ministry said the move would undermine the image of the tournament and be detrimental to millions of Ukrainians and Poles.
Poland – which is co-hosting Euro 2012 – has also criticized any boycott.
Several European leaders are considering cancelling their trips to Ukraine, in protest over the treatment of jailed former PM Yulia Tymoshenko.
Yulia Tymoshenko, who is on hunger strike, alleges she was beaten by prison guards.
The statement from the Ukrainian foreign ministry said sport events were designed to bring unity, and criticized what it said were attempts to politicize them.
“We view as destructive attempts to politicize sporting events, which since ancient times have played a paramount role in improving understanding and agreement between nations,” the statement said.
“A successful championship will be a victory not for politicians, parties or ideologies, but for all Ukrainians and Poles. Its failure will be a loss for millions,” it said.
Ukraine denounces a threatened EU boycott of next month's Euro 2012 football championship as "destructive"
Austria has said it will boycott all the matches in Ukraine, while the Netherlands said it will not attend unless Yulia Tymoshenko’s treatment improves.
On Thursday, EU officials said European Commissioner Jose Manuel Barroso would not be attending.
German Chancellor Angela Merkel is also reported to be considering boycotting the event, while the UK says it is undecided on whether to attend.
Meanwhile, five European presidents – from Austria, the Czech Republic, Germany, Italy and Slovenia – have said they will not attend a Ukrainian summit of Central and East European leaders next week in Yalta.
In an attempt to ratchet up the pressure further, Germany earlier said the EU is prepared to delay a trade agreement with Ukraine.
German Foreign Minister Guido Westerwelle said that “with our EU partners we are unanimous that the EU Association Agreement with Ukraine cannot be ratified as long as the rule of law in Ukraine does not develop in the right direction”.
But Ukraine’s deputy prime minister has said Euro 2012 is on track and UEFA – European football’s governing body – had not complained.
“The tournament is ready and on 11 May we will be transferring the control of the four stadia to UEFA.”
Yulia Tymoshenko, a former prime minister, was jailed last year for abuse of office, in a trial condemned by the West as politically motivated.
She is an arch-rival of Ukraine’s President Viktor Yanukovych, who beat her to the presidency in February 2010, avenging his defeat in the 2004 Orange Revolution.
The opening games of the month-long Euro 2012 will be played on 9 June.
Twenty five out of 27 EU leaders have signed a new treaty to enforce budget discipline within the bloc.
The “fiscal compact” aims to prevent the 17 eurozone countries again running up huge debts.
It must now be ratified by individual parliaments and, in the case of the Irish Republic, a referendum.
UK Prime Minister David Cameron, who with the Czechs refused to sign, said his proposals for cutting red tape and promoting business had been ignored.
But the newly re-appointed President of the European Council, Herman Van Rompuy, said British calls to boost the EU economy were being taken seriously and he had sought to re-draft the summit’s conclusions accordingly.
The fiscal compact is what emerged after David Cameron vetoed plans to change the EU treaties to enforce greater budgetary discipline back in December.
German Chancellor Angela Merkel described it as a “great leap”, a first step towards stability and political union.
These new powers may face an early test as both Spain and the Netherlands have admitted they will miss targets for reducing their deficits.
While there has been a change of emphasis at this summit, “from crisis mode to growth mode” in the words of one senior official, it will be difficult to achieve whilst tough spending cuts are being made.
In a speech at the signing ceremony, Herman van Rompuy said: “This stronger self-constraint by each and every one of you as regards debts and deficits is important in itself.
“It helps prevent a repetition of the sovereign debt crisis. It will thus also reinforce trust among member states, which is politically important as well.
“The restoration of confidence in the future of the eurozone will lead to economic growth and jobs. This is our ultimate objective.”
Christian Wulff, Germany’s president, has announced his resignation, after prosecutors called for his immunity to be lifted.
Christian Wulff, an ally of Chancellor Angela Merkel is embroiled in a scandal over a home loan that he accepted when he was premier of Lower Saxony.
Chancellor Angela Merkel cancelled a visit to Italy on Friday to deal with the crisis, and she will give a statement shortly.
Christian Wulff, Germany’s president, has announced his resignation, after prosecutors called for his immunity to be lifted
According to German media, the crisis is unprecedented in post-war Germany.
The affair will be no more than a headache for Chancellor Merkel, whose approval rating is high among the German people.
However, it comes at a time when Angela Merkel does not need any new headaches, as Germany wrestles with the Eurozone debt crisis.