"I think (I will decide) after the summer when all this period of races, then the break and then Belgium and Monza are over," said Alonso.
"They are very important races for us to try to get this fourth position in the constructors' championship. And after that will be time to think about what the possibilities are for next year."
"We need to work as soon as possible on next year's car, but this year's position at the end of the championship is very important for the team," he said. "It's not the same if you finish seventh or you finish fourth, which is the area that Renault is moving towards now.
"We are seventh in the constructors', but we know that our target is to finish fourth and we can do it. So that will make a big change in the budget and everything for next year, so we need to push in two parallel projects, the R28 and the R29, as hard as we can I think."
If Renault fail to get into the top three in the constructors championship, Alonso has the option of leaving the team at end of the year.
The most likely place where Alonso will go is to Ferrari where he may take over Felipe Massa's seat. But with Massa picking up the pace and some wins, not to mention the lead in the drivers championship it looks very unlikely that Alonso will be in a Ferrari. But two other teams are looking at getting Alonso's services: Honda, where there motto is "We always work towards next year" and Red Bull Racing. Both have drivers that are at the twilight of thier carrers and both could use a guy like Alonso to help get thier teams on track.