A clause in his current deal means he can leave over the summer after Milan failed to clinch Champions League qualification.
Kaka told Sportmediaset: "I am happy. I can improve and do better. My desire is to stay but there are personal things to fix and decide. The fans should not worry, I will not play with them.
"It will be my choice, that of the future, the intention is to remain but also I must weigh up personal factors and the family."