If you tell a guy how you feel about him, and he does not respond what does that mean? How can a guy sit on the phone with a female until 1am, or 2am and not have any feelings for her? Can that be ...
You didn't specify the "how you feel" about him, but i assume you mean you like him deeply. If he does not respond there are many reasons, one may be he likes you too and is embarrased or insecure about expelling his feelings, or he feels uncertain how he feels about you. Maybe he thinks your not the absolute partner. The fact that he doesn't answer means any number of things, it's not a black and white thing, it has to do with context and the situation. It's not a question which has an easy answer, only you can come up with it. Based on your understanding of the relationship you should have a perspective on what he means by the remark.