"Yes, of course it's true," he told The Miami Herald while promoting his new South Beach restaurant Villa Azur. Reports that the two were to be hitched first surfaced in January.
The Oscar-winning actress, 45, co-starred with Martinez, 46, in the 2010 film "Dark Tide."
Berry has been married twice before -- to baseball player David Justice in the early 1990s, and to singer Eric Benét in the early 2000s. She has a daughter Nahla, who turns 4 this month, with Gabriel Aubrey.
Martinez set the record straight regarding the emerald engagement ring he gave Berry, too. He said it is designed by Robert Mazlo of Paris, whom Martinez called "a real artist" who has been making jewelry for "kings and queens for many centuries."