The actors, both 43 and parents to Violet, 10, Seraphina, 7, and Samuel, 4, announced last June they had made the "difficult decision to divorce" after 10 years of marriage. No divorce documents have been filed.
"I am a giant fan of Jennifer," Affleck said on CBS This Morning Friday, the day his new film, Batman v Superman: Dawn of Justice, hit theaters. "She's just a fabulous person. She's just a wonderful person. She's a great mother. She's a real talent."
"Life doesn't always turn out exactly the way you want," he said. "We're doing our very best and we're putting our kids first and that's how we're focusing on our day to day lives and we don't know what the future's gonna hold, but each step that we take is one where we prioritize our children and everything else comes second. And she's just so good at doing that and has set such a good example and a lead that I follow. She's somebody that I admire and respect and remain excellent friends with."
Affleck and Garner still live together with their kids and "have no plans to change that arrangement," a source told E! News earlier this month.
A month after the split announcement, Affleck was linked to his children's nanny. He has denied anything romantic went on between them. Last month, Garner broke her silence about the split and the nanny in a bombshell interview with Vanity Fair, saying she and Affleck "had been separated for months" before she ever heard about the nanny and that the woman "had nothing to do with our decision to divorce."
"The Vanity Fair article was her speaking her mind and being who she is and that's somebody that I know and talk to every day," Affleck said on CBS This Morning. "So it was simply, you know, her being who she is, is being extraordinary and being somebody articulate and being somebody who I respect a great deal."
Affleck recently told E! News' Catt Sadler that Garner is "a superhero mom," adding, "I'm really lucky to have her as a partner to co-parent these kids with. We try our best, we put them first and that's what we do."
Garner had talked about her and Affleck's co-parenting on the Today show last week.
"We're doing really well," she said. "The kids are great. They'll be getting up in the morning and going to school soon, and Ben is there and he'll be taking them. We will make it work."