Boston Mayor Martin J. Walsh is renewing concerns about the IndyCar road race slated for next fall, warning local promoters to “pick up the pace” in getting approvals from city and state agencies for security and traffic plans.

Walsh, in an interview on Boston Herald Radio’s “Morning Meeting” show, said he still supports the proposed Grand Prix-style race around the city’s waterfront but cautioned time is running out to finalize agreements to hold the event next Labor Day.

“I certainly think that Indy has to pick up the pace here,” he said. “Because we’re talking in September and it’s January pretty much. So I think they’re going to be up against it pretty soon, up against the clock.”

Walsh also confirmed that he called Mark Miles, the head of the IndyCar parent organization, several weeks ago when it appeared the Boston race was in jeopardy because of the local promoter’s failure to get approval from the state.

“I called them and said we need to get on the ball here and straighten this thing out,” he said.

After that call, the city and state agencies signed a “letter of intent” with local race organizers, Boston Grand Prix, that stipulates no taxpayer money will be used for the event — but Walsh said other issues haven’t been resolved.

“I still think there’s a fair amount of planning that Indy has to do to finalize it and make everyone comfortable here,” he said.

Walsh signed a memorandum of understanding with Boston Grand Prix in May, but that agreement has since been scrapped and the city and state are now negotiating on permits or agreements to use the city’s streets for the high-speed IndyCar course.

The mayor said organizers haven’t even finalized their own plan for the course and other details of the weekend-long event so the city and state can review and approve them.

“There’s some issues around safety plans, there’s issues around traffic plans, there’s issues around different types of plans that they owe information on,” he said.