Ronaldo gave the controversial interview in November in which the 37-year-old also criticised the club and said he "felt betrayed".
The forward has since left United in a "mutually agreed" exit.
"Until that moment he never told me 'I want to leave'," said Ten Hag
Speaking to UK journalists for the first time about Ronaldo's exit on United's mid-season trip to Spain, Ten Hag said that once he saw the interview there was no way back for the player.
"I have seen most of it," the United manager said. "I have to do it. It is part of my job.
"The interview, I think, as a club you can't accept. To make that step he knew the consequences.
"But before he never told me. Until that moment he never told me 'I want to leave'."
"In the summer we had one talk," said Ten Hag.
"He came in and said 'I will tell you in seven days if I want to stay'. He came back and said he did. Until that moment [the interview] I never heard anything [else]."
Ten Hag insists he wanted Ronaldo to stay.
"I like to work with world-class players," he said. "I know they can make a difference and help you to achieve your objectives.
"I wanted him to stay from the first moment until now. I did everything to bring him into the team because I value his quality. We wanted him to be part of our project and for him to contribute to Manchester United because he is a great player and has such a great history."