The Swiss team has struggled this year but a takeover earlier in the season has given them financial stability and secured their future.
"It's been a difficult year, not just for me but for the whole team," Nasr told Brazil's Globo. "Who is in our situation knows that you cannot just analyse the results, but I have always tried to pull the team up and look at the positive side of things -- and this work will be critical for 2017."
"Yes, we had contacts," he said. "I had had options, but at the moment we have not made a decision. It's a matter of waiting.
"What I see is that Sauber is on a constructive path since the arrival of the new investors. It is an attractive team and I hope to announce my future soon," added Nasr.
Bahrain International Circuit - Winter testing