Manchester City have made clear their intention to sign Nasri before the close of the transfer window and, with just one year remaining on his contract, Wenger must persuade the player to commit to an extension if he is to avoid losing him.
"Ideally I want Samir Nasri to stay, but as much as we were in a strong position on the contract side with Cesc, the situation is a bit different," he said. "Hopefully we can sort the situation out."
Nasri, though, has expressed disappointment that Arsenal fans sang an offensive song about him at Newcastle. "I heard what the fans were singing about me on saturday and it is really disrespectful because i'm still a arsenal player," he tweeted.
Meanwhile, Arsenal have been linked with Shakhtar Donetsk star Jadson and City forward Carlos Tevez as they attempt to strengthen the squad before the end of the month but, asked if he was looking to sign the duo, Wenger said: "No. I have not envisaged one or the other."
He added: "What I want to say is that we are not frightened to spend money, but we have to be convinced the player is better than what we have. That is our main concern, to bring quality. We have quality, but want to add more quality."
Arsenal will be without suspended duo Samir Nasri and Robin van Persie for the Champions League qualification first leg against Udinese at Emirates Stadium on Tuesday, while Jack Wilshere is missing through injury and Tomas Rosicky faces a late fitness test.
Wenger also confirmed he expects to appeal Gervinho's red card against Newcastle on Saturday. "I am likely to," he said.