The "How Do You Know" actress first told UsMagazine.com she was engaged to CAA agent Jim Toth Tuesday, though Phillippe decided to wait two days before commenting on the couple's relationship.
"I'm very happy for both Reese and Jim," Phillippe, 36, tells the Daily News in a statement. "I wish nothing but the best for the mother of my children."
Phillippe, who was married to the 34-year-old actress for seven years, previously opened up to Ellen DeGeneres about how he and Witherspoon co-parent daughter Ava, 11, and son Deacon, 7.
"Things are great," he said in May. "It is so important as divorced parents to keep that connection. It makes the kids feel better that the parents are interacting ... We go to all the school events together, and we're there for each other."