The 26-year-old, along with the likes of Didier Drogba and Nicolas Anelka, is out of contract at the end of the season.
Kalou's Stamford Bridge future had looked uncertain but Villas-Boas has revealed the striker had been offered a fresh terms.
The former Feyenoord man has made just two Premier League starts under Villas-Boas, leading to speculation over his future.
However, the Portuguese is keen to retain Kalou and he is not worried by the mental state of the trio while talks continue.
"Kalou was offered a contract and hopefully we will continue talks," he told the club's official website.
"In January these players are available to discuss their future. We'll continue talks until we reach an agreement or not.
"The fact that they are emotionally tied to this club - like Nico (Anelka) - too, means we can count on them while they are negotiating. Their loyalty to the club will never be in question."