Wilshere's current deal expires at the end of the season, and he is free to discuss a move abroad when the transfer window opens in January.
The England international had said earlier this week he was in the dark over his future at the club.
But Wenger said: "I will talk to him. I said [I would] at the end of December.
"We are at the beginning of December so it's true that it's not far, but I wanted to see, as well, how much he can contribute and how he will last physically.
"It is, of course, for him to be happy to be here as well, that is important. I consider him as an Arsenal man and, for him, it's important as well to feel happy here."