The 33-year-old has been without a club since departing West Ham United in the summer, but it had been suggested that he could turn his back on football in order to pursue an acting career.
However, the Norwegian has confirmed that he has been training with the Italian club.
He told La Gazzetta dello Sport: "I'm ready. I feel good and I've worked with the team over the last two weeks.
"I've travelled around and been to the cinema a few times but now I'm ready to give my all for Inter. I wasn't expecting the call - life is full of surprises."
Carew scored 24 goals in 91 games for his country.