Paul Walker and Vin Diesel's deep friendship obviously went beyond just being co-stars
-- and now Diesel has found a touching way to keep the late Walker's memory alive.
"He [Walker] was in the room. There's no other person that I'm thinking about as I'm cutting this umbilical cord," he told Today's Natalie Morales. "I knew he was there and I felt like, you know, a way to keep his memory a part of my memory, a part of my world."
Diesel and his girlfriend, Paloma Jimenez, announced the arrival of Pauline -- their third child together -- on March 16. The two are already parents to Hania Riley Sinclair, 6, and son Vincent Sinclair, 4.
Clearly, Diesel and the rest of the Fast & Furious family are still reeling from Walker's death, particularly as they do promotion for the franchise's latest installment, Furious 7.
"This was a labor of love," he added. "It was in some ways the hardest movie I ever had to do."
Furious 7 will hit theaters on April 3.
Last November, ET caught up with Walker's father, Paul Walker III, when he talked about his loss and paid tribute to his son.