Sergey Sirotkin says he would like to stay at Williams in 2019.
Days ago, the boss of the Russian driver's major sponsor, SMP Bank, said he is not sure if the backing of the struggling British team will continue.
And at Sochi, Sirotkin's management was spotted in conversation with Dr Helmut Marko, triggering rumours he and SMP might be eyeing a move to Toro Rosso.
"So far nothing has been decided," Sirotkin said in Japan.
"I repeat that I am together with the team and together we want to get out of the situation that we find ourselves in."
He admitted that SMP Racing, headed by Boris Rotenberg, is concerned about Williams' 2019 form.
"I think both SMP Racing and I have the same answer -- we want to be doing better than we are doing now. But the last thing I want to do in our situation is say we give up.
"We have already made great efforts, so I don't see the logic in stopping now without achieving a result," Sirotkin added.