Paul Walker and Vin Diesel
Paul Walker and Vin DieselFacebook/Vin Diesel

It is no secret that Vin Diesel has been having a tough time dealing with the death of Paul Walker, and fans got to see how much the actor missed his late friend during a special screening of "Furious 7" recently.

Diesel got emotional and choked up at a Los Angeles screening of "Furious 7" while talking about his "best friend" Walker, who passed away in November 2013 following a car accident.

Speaking at the event, Diesel said that this made "Furious 7"  the hardest movie he has ever done. "This film was a labour of love. It was in some ways it was the hardest movie I've ever had to do because the relationships you see on film are so real. Please from my heart, know that we made this movie from our hearts. And know that this is our gift to you and more importantly, it's for my brother there," Diesel said, according to Mail Online.

Diesel and Walker shared a good rapport and since the latter's death, Diesel has been giving fans glimpses into their personal relationship through Facebook posts and pictures.

Divulging more about their relationship, Diesel said that although they started out as strangers, they became iconic together over the 15 years they worked together. Over the course of time Walker started looking up to him as a brother, said Diesel.

"He knew I was the big brother. It's how that relationship started. He knew that I was gonna fight for him for the rest of my life," Diesel told Access Hollywood on Sunday. "We're from two different places. I'm from the east coast. He's from California. We couldn't be further apart in some ways and yet we were so much alike," he said.

"Furious 7" is the last instalment of the "Fast and Furious" franchise, in which Walker will be seen as law-enforcement officer Brian O'Connor. Although Walker had completed a number of his scenes before the tragic accident, his brothers – Caleb and Cody -- were roped in to help complete a few other scenes written for Walker.

"Furious 7" opens in theatres on 3 April. Besides Walker and Diesel, the film stars Dwayne Johnson, Michelle Rodriguez, Jordana Brewster, Tyrese Gibson, Chris Bridges, and Jason Statham among others.