“My son will be an American, but I remain French,” the French actor told People.
The actor, who is honorary president of the Champs-Elysées Film Festival, made the statement in the opening night of the event.
Martinez, who he has been living with Halle Berry in the past two years in the US, spoke about the differences between the French and the American media.
“I’m French — it’s less important,” he explained. “Meaning, I remain a Frenchman in America, but I adapt to American culture. I feel good there — but I’m still a foreigner.”
“My son will be an American,” Martinez added.
In April, when the happy news came out, the actress was around three months along and she is due in the fall.
It will be the first child of the Halle Berry-Olivier Martinez couple. Halle Berry has a daughter, Nahla, 5, with her ex-partner, Gabriel Aubry.
Berry and Martinez got engaged during the 2011 holiday season.
Frenchman Olivier Martinez had a long-lasting relationship with Australian singer Kylie Minogue, with whom he broke up in 2007.