French President-elect Francois Hollande has started putting together a new government after defeating conservative incumbent President Nicolas Sarkozy in Sunday's runoff election.

Final results show Mr. Hollande won 51.6 percent of the vote to Mr. Sarkozy's 48.4 percent. The 57-year-old Socialist will take office on May 15.

The vote reflected citizens' disapproval of the country's spending cuts and high unemployment. Mr. Hollande has been vocal in opposing many of France's economic austerity measures. He has promised to reopen talks on European Union austerity measures championed by German Chancellor Angela Merkel and Mr. Sarkozy.

Ms. Merkel said Monday that the EU's fiscal pact is nonnegotiable. But she said she would welcome the president-elect “with open arms,” and that they would work together closely.

U.S. President Barack Obama telephoned his congratulations to Mr. Hollande on Sunday and invited him to the White House before the Group of Eight and NATO summits later this month.

The White House says the enduring alliance between the United States and France is as strong today as it was last week.

Mr. Hollande will be France's first Socialist leader in almost 20 years. He has promised to move quickly to implement higher taxes on the rich to help finance increased state spending.

The White House says Mr. Obama telephoned President Sarkozy on Monday to thank him for his “strong leadership,” “friendship and partnership in challenging times.”