Is this a problem?

This guy Iv been seeing for almost a year now won't fully commit. We have been best friends ever since high school and have a very complicated relationship, we fell out of touch and this past year got back in contact. Things have been great and our connection is really strong, we both have feelings for each other. There's no denying that. But why is it so hard for him to make it official? How can I bring something like this up and not ruin what we have? I don't want to seem needy or pushy but id like to know where we stand and how he really feels?

Why do you think he doesn't talk about going further? Should I be worried.