Kamui Kobayashi has insisted that he is doing everything he can to earn a drive in Formula 1 next year, but has conceded that his task will be difficult without financial backing.
However, Kobayashi remains optimistic that he can stay on the grid for 2015.
He is quoted by GPUpdate.net as saying: "I am concentrating all my energy on keep racing in Formula 1. I believe in Formula 1. I'm here without money but I want to win in Formula 1 without money, but it's very difficult.
"It's many driver's dream but I need to make the dream come true. That's why I'm here. In the past I didn't mind because I could get an experience opportunity and at least I can say to other teams I have experience. At least at this point I think my decision this year was good to prove what I can do.
"I've been looking for some weeks. But still, technically, I am a Caterham driver, but I think from now I can do more and I need to negotiate to see what I can do."
Kobayashi, who has had stints with Sauber and Toyota in the past, revealed that he only learned of Caterham's absence from the US Grand Prix via the internet and that he has had little contact with the team's hierarchy.