Ryan Reynolds believes his 17-year friendship with Hugh Jackman is similar to a marriage.

The pair first met back in 2008 when they made superhero movie 'X-Men Origins: Wolverine' together in Australia and they have been close pals ever since with Ryan, 47, admitted the "secret sauce" to their bromance is treating it like a true relationship because they can tell each other anything and he's "genuinely rooting" for his pal to succeed.

Ryan told PEOPLE: "I think the secret sauce to a long-lasting Hollywood friendship is not too dissimilar to having a partner or a marriag.

"I am genuinely rooting for you, all the time. I want you to win. It’s the same way I feel about [wife] Blake [Lively]. As I'm rooting for her, I know she's rooting for me, and it's why we're so connected."

Hugh, 55, added of the special friendship: "Ever since I've known you, and I would say in particular in like the last five, 10 years, we've had more time where we go for our walks because you're an unbelievable listener.

"So you can tell me anything and I can tell you anything, and I don't feel like you're going to be judging or necessarily giving me the answer: ‘Do this.’ And I think that has been the key."

Ryan revealed their friendship got off to a good start when they met on set and Hugh welcomed him to the cast with a hug. He added: "I was walking through the trailers, jet-lagged, disoriented, feeling really green and kind of out of my depth, and there was no script to look at. It was just like, what's going to happen?

"And I heard my name, ‘Ryan!’ in between these trailers as I was walking. And it was you. Just the fact that you knew my name meant so much to me. And you came over, you gave me a big hug and you said, ‘Welcome aboard'."

The pair are back in action together for a new movie featuring their superhero characters 'Deadpool Wolverine' and Hugh revealed Ryan welcomed him onboard in a similar way.

He told the outlet: "The first day of this [movie] and you came, and you did the same thing. You came over and you went: 'Steve!'"