"I'll be going to London in the spring to do my role, and I get to do a little song and dance number," the actor explained to Entertainment Tonight about the role.
"I gotta be a part of it," he continued.
Van Dyke famously appeared as chimney sweeper Bert alongside Julie Andrews as Mary Poppins in the 1964 original in addition to portraying bank manager Mr. Dawes.
The upcoming sequel, due in theaters Dec. 25, 2018, will be directed by Rob Marshall and stars Emily Blunt in the title role alongside Lin-Manuel Miranda as Mary's friend Jack the lamplighter, Colin Firth as banks president William Weatherall Wilkins and Meryl Streep as Poppins' cousin.
The film takes place 25 years after the original and features a grown-up Jane and Michael Banks as they encounter the magical nanny once again.