The Italian company took over as the sole supplier to F1 at the beginning of last year, with Bridgestone following Michelin in leaving the sport.
Pirelli's tenure has been dogged by controversy, with many saying that they have turned F1 into a lottery and called for the return of competing manufacturers.
However, should such a proposal go through, Pirelli would not be involved.
"We work for the sport. The sport has to decide what it wants," said Hembery.
"If it wants a tire war and procession racing again, like it did in the early 2000s, when the audience disappeared, than that's one approach. It's not for us to decide.
"We will wait and see if the rules change. If they change, then we will consider it. At the moment the teams are certainly not interested in a tire war.
"What does it really mean to have a tire war? If it means spending 100 million Euros to go half a second quicker – and you can't even prove that you have the better tire, because the teams will dominate still – it is pointless," he added.
"Ultimately no-one could really make out what tires were on what car when there was a tire war. Nobody knew, because all the money was being spent on trying to find performance that the public couldn't see. And if the public can't see it, we don't understand it." Planet F1