JOHN Travolta has revealed that James Gandolfini's father used to buy tyres off his dad and that The Sopranos star was his rock when his son died.

Travolta, 59, co-starred with Gandolfini a number of times, including in the movies Get Shorty and Lonely Hearts. The pair are both from New Jersey and Travolta told Good Morning America that he was Gandolfini's inspiration to get into acting.

"He would see pictures of me on the wall from movies and he decided that he wanted to be an actor," he said,

51-year-old Gandolfini died this week in a Rome hotel from a heart attack.

Travolta said Gandolfini turned up on his doorstep to support him and wife Kelly Preston after their son Jett died of a seizure in 2009 at the age of 16.

"James went out of his way to come to Florida and he would not leave Florida until I was okay, or he felt that I would be fine," Travolta recalled. "After a week I said, 'Jim you can go ... we'll be fine. I've got a lot of support here.'"

"But the idea that in our profession someone would go out of their way and not want to leave you until he felt you were okay, that's the kind of soul that James Gandolfini was," Travolta said.

The Grease actor said he would now return the favour to Gandolfini's family, including his wife Deborah, and his children Michael, 13, and Liliana, 8 months old.

"My goal is to make sure that his family is okay," Travolta said. "His little boy, I watched him grow up, and his brand new little girl. We'll just make sure they're taken care of. That's the whole idea," he said.