Emmanuel Macron told the Journal du Dimanche newspaper on Sunday that the final investment decision "may be confirmed next September."
The decision was expected in May but EDF, which is majority-owned by the French government, decided Friday to take more time to consult with the company's unions. Some of them have expressed concerns about the financing of the $27 billion project.
Macron insisted the project must not be further delayed.
The Hinkley Point nuclear power plant could ultimately produce 7 percent of British electricity and create 25,000 jobs, according to EDF. It had been due to start producing electricity in 2023.