Shawn Mendes says he can always count on John Mayer.

Shawn Mendes

Shawn Mendes

The 18-year-old musician has been able to rely on the 'Gravity' singer for help in navigating the world of fame ever since the pair performed in Toronto together in April, and Shawn has now said his regular calls with John, 39, have helped him lower his "anxiety" levels.

He said: "[Performing with Mayer] was obviously incredible. As a person I really relate to him and I think he's awesome. He's a dude I can call -- for him to be like, 'Hey man, how's life? You're gonna be fine.' And my anxiety levels down to a one instead of a 55. That's something that's really nice."

And the 'Stitches' singer is "excited" for the next phase of his musical journey after becoming friends with John, as he's realised how things "only get better" with the more he works at his music.

He added to People magazine: "It's cool to be able to see someone like him be so creatively inspired after so many albums and after so much touring. It gets me so excited to know that I can always be this pumped up -- and you only get better, because Mayer has only got better."

Meanwhile, the 'Treat You Better' hitmaker recently revealed he hopes his songs will serve as "anthems" for his fans, and hopes to someday embark on ventures that "make a difference."

He said: "I want to create anthems for people. I want to create anthems for big moments in their lives.

"I don't want my music to play for a few months and then go away forever. And not only that, I want to do incredible things that make a difference too.

"I think it's not only about the music you release, it's about the things you do while you're making the music."