"100 percent. I've got one more year left on my contract which is 2019, God willing I'm a part of that," he told Jones when asked about next year's tournament in Japan.
The question whether Williams would play a second stint for the Roosters was put to him in a sit down interview on Sunday Night with Matty Johns on Australia's Fox Sports channel earlier this month.
"Family don't tell everything bro," Williams said with a smile. "Come on brother?" he said to Johns.
"Honestly, I'm 34 next year. I'm just happy doing what I love doing. I'm really concentrating on things off the field. I really want to affect my people – Pasifika people. With that comes responsibility. I need more knowledge in that field, which I'm doing. I'm studying. I'm doing my coaching papers.
"I don't know. I feel once, God-willing, I can make it through next year and make that World Cup side, then after that…A, I have to keep the wife happy and B, if I do play on, it will have to be a place where I still have a voice."
He returned the league in 2013, leading the Roosters to a title that year.
Williams was confident the young midfield combination of Ngani Laumape and Jack Goodhue will step up tomorrow night against Australia with himself and Ryan Crotty on the sidelines.
"I've got no doubt they'll step up to the plate. They won't just play, they'll deliver," Williams told Jones said before talking up Goodhue.
"He's fit, he's strong and he's fast. He's got really good skills as well," he added.
