"If he could see for himself that all of you have showed up to show my brother love at this hard time, and the family gets to see all of you show the love that you've shown Paul, it's going to stay with me forever," Diesel told the crowd in a video posted byKTLA-TV.
"I just wanted to say thank you," he added. "Thank you for coming down here and showing that angel up in heaven how much you appreciated him."
A few hours before, Diesel honored his Fast and the Furious co-star on Facebook, writing: "Pablo, I wish you could see the world right now... and the profound impact, your full life has had on it, on Us... on me...
"I will always love you Brian, as the brother you were... on and off screen," Diesel concluded, referencing Walker by his Fast and the Furious character's name.
Along with a photo of himself and Walker, Diesel also included a quote from Scottish poet Thomas Campbell: "To live in the hearts we leave behind, is not to die."
Walker and his friend Roger Rodas died Saturday in a fiery car crash in Santa Clarita, Calif. The investigation into his death is ongoing with speed being considered a factor.
On Monday, the actor's family posted a statement to Walker's Facebook pagethanking fans for their support. "Paul Walker's family appreciates the outpouring of love and goodwill from his many fans and friends. They have asked, in lieu of flowers or other gifts, that donations please be made to Paul's charity Reach Out Worldwide.
"Its comforting for them to know that the son, brother, and father they love so much is equally adored, respected, and appreciated by so many," the statement continued. "Paul founded the organization with the genuine desire to help others, and it's important to his family to keep his memory alive through ROWW."
Watch Diesel's speech below: