Paul Hembery believes Pirelli are in the "most bizarre situation" given that they still do not have a contract for next year's Championship.
Pirelli entered Formula One in 2010 on a three-year deal as the sport's sole tyre supplier. That deal, though, expires at the end of this season.
As yet the Italian tyre manufacturer does not have a new contract in place meaning that while they need to press ahead with plans for next year, including commercial deals with the individual teams, nothing is actually guaranteed.
"It's the most bizarre situation we're in really," Hembery explained to ESPNF1.
"We've got our agreements in place with the vast majority of people involved; there's not a clearly defined process but we're going forward, getting the teams signed up, we've got the promoter signed up, we're working on 2014.
"We can only work with what we're being asked to do. We've got cooperation from the teams, we've got cooperation from the promoter and we've had ongoing cooperation from the FIA so until somebody tells us any different we don't really know what we should be doing differently."