The Italian tyre manufacturer returned to the sport in 2011 after a 20-year absence. Its supply contract expires at the end of this season.
Pirelli is already in talks over a new deal that Hembery hopes is finalised soon and that secures the company's position as F1's tyre supplier for the long term.
Hembery made it clear, however, that the conditions have to be right for Pirelli to want to stay involved in grand prix racing in the long run.
"We'd love to stay longer in the sport, because that's the only way you can really leverage the investment," Hembery told AUTOSPORT. "The costs are significant.
"We get a contribution from the teams and like everybody we have to go back every time and answer to our board as to why we are doing something and what return do we get. A lot of the return is coming from the trackside advertising.
"That gives us visibility and so far that has stacked up. But we are not immune to the world economy.
"We are a global business and when there are issues in some geographical markets you need to compensate.
"Big companies have to make big decisions in motorsport, and you always have to justify it. So if it's not the right thing to do you have to bite the bullet.
"We are no different to car manufacturers that have come and gone. We are trying to maintain our position but there are limits and we can't exceed those."
Hembery said the Pirelli board has already approved the decision to stay in F1 as long as the right deal is in place.
"We have provisional approval from the board," he said. "Obviously that is based on certain assumptions.
"If those assumptions are met, and the depends clearly on what happens with the promoter and the teams, then we have approval to go ahead.
"If the project costs start to change or if the investment becomes far too great for the return, then clearly that's a different decision."
He also emphasised that Pirelli will not be increasing its fee to F1 teams.
"We are looking at that, but I can guarantee there will be absolutely no increase," Hembery said.
"We are one of the few who will not be asking for an increase. I keep reading about many others involved in the sport asking for quite substantial increases, but the only thing I do know is that we won't be asking for any increases."
He also said that Pirelli's deals with the teams will continue to be exactly the same, with no preferential treatment for any outfit.
"Every single contract will be identical. As far as we are concerned all the teams are equal partners and we have to make sure we give them an identical level of support."