LONDON (AP) — The IOC is bracing for a possible “overwhelming wave” of interest from national Olympic committees in bidding for the 2024 Summer Games.

The International Olympic Committee on Thursday launched a new “invitation phase” to work with potential 2024 contenders ahead of the Sept. 15 deadline for formal submission of bids.

So far, Rome and Boston are the only declared candidates, and Germany has said it will submit a bid either from Berlin or Hamburg.

IOC executive director Christophe Dubi expects a high level of interest.

He says there could be a “decent but limited” number of responses from cities already bidding or planning to bid, or “it could be an overwhelming wave of questions from NOCs saying, `we’d be really interested to get a view on what it means to organize the games.'”

Copyright 2015 The Associated Press.