Knicks president Steve Mills and general manager Scott Perry revealed Porzingis' ultimatum during a fan forum series Wednesday.
"When he walked into our office -- my office and Scott was sitting there with me -- and point blank said to us, 'I don't want to be here. I'm not going to re-sign with the Knicks, and I'll give you seven days to try and trade me or I'm going back to Europe,'" Mills said.
The Knicks eventually dealt Tim Hardaway Jr., Courtney Lee, Trey Burke and Porzingis to the Mavericks in exchange for Dennis Smith Jr., DeAndre Jordan, Wesley Matthews and two future first-round draft selections in January. Porzingis was unhappy with the direction of the organization, which led to his trade request.
Porzingis is scheduled to become a restricted free agent this off-season. He has a qualifying offer worth about $4.5 million for the 2019-20 season, according to Spotrac.
League sources told The Athletic that Porzingis is planning to sign the qualifying offer instead of testing restricted free agency. He could become an unrestricted free agent in 2020.
Porzingis didn't play last season as he continued his recovery from a torn ACL. He averaged 22.7 points, 6.6 rebounds and 1.2 assists in the 2017-18 campaign.