LONDON — Emmanuel Macron will take office as France’s next president on May 14, President François Hollande announced on Monday, a day after Mr. Macron, an independent centrist, defeated Marine Le Pen in a battle for the country’s leadership.

Mr. Macron appeared beside Mr. Hollande at a ceremony at the Arc de Triomphe to observe the 72nd anniversary of the end of World War II in Europe. He did not make a statement, but his attention will already have turned to the choice of a prime minister and to the legislative elections of June 11 and 18, when all 577 seats in the National Assembly — the lower, more powerful house of the French Parliament — will be up for grabs.

Expectations could hardly be higher. “Beyond the symbols, the new, optimistic president of this country in depression will have to demonstrate by concrete signs, very quickly, that he received the messages from this extraordinary campaign,” Jérôme Fenoglio, the editorial director of Le Monde, wrote in a front-page editorial.

Mr. Macron’s year-old political movement plans to field candidates — a mix of newcomers and more experienced figures — for all of the seats. In the meantime, he is expected to name a prime minister and a cabinet.