In a story posted Wednesday morning, WSJ magazine reported that Richards said "it's time for the snip — you can't be a father at that age. Those poor kids!"
The 74-year-old Jagger welcomed his eighth child in December 2016.
But Richards says "I deeply regret the comments I made about Mick" in a statement released Wednesday afternoon. He says his words "were completely out of line" and that he apologized to the Rolling Stone frontman in person.
Richards famously wrote about his issues with Jagger in his 2010 memoir, "Life."
WSJ interview with Richards: https://www.wsj.com/articles/the-wisdom-of-keith-richards-1519826136