United Kingdom, May 1 -- Robert De Niro doesn't understand "what the big deal is" about his child coming out as trans.

Airyn De Niro - whose mother is actress Toukie Smith - recently opened up about "stepping into this new identity" as a trans woman and now her Hollywood star father, 81, has insisted that he "loves all" of his children no matter what.

He told PEOPLE: "I loved and supported Aaron as my son, and now I love and support Airyn as my daughter. I don't know what the big deal is, I love all my children."

The 'Godfather Part II' star is also father to Drena, 57, and Raphael, 48, with his first wife Diahnne Abbott, Julian, 29, with ex-girlfriend Toukie , as well as Elliot, 26, and Helen, 13, with ex-wife Grace Hightower.

In Apr...