French President François Hollande Monday named Interior Minister Manuel Valls as his new prime minister to lead a "combative government."
51-year-old Valls replaces Jean-Marc Ayrault in a government reshuffle triggered by a rout for his Socialists in local elections.
Addressing the nation in a short televised speech, Hollande said a key objective for the new government would be pursuing the so-called "responsibility pact" to lower employers' costs in order to spur job creation.
Spanish-born Anne Hidalgo defeated her conservative rival to win the top job in the French capital.
Hidalgo perviously served as a deputy to the outgoing mayor, Bertrand Delanoe. She won with promises to build new public housing and make day care more affordable for Parisian families.
Many political observers regard the office of Paris mayor as a step towards the French presidency.
However, Hidalgo's Socialists did not fare well in many other French towns and cities, losing ground to the anti-immigrant and anti-European Union National Front party.
The elections were seen as a referendum on the unpopular president, François Hollande.
Voters are angry about the sluggish economy and high unemployment.