HE is afraid that he will disappoint you in some way or is not ready for a commitment with you.
I agree with the disappointing part. I have said this to women before because I always felt that I would disappoint them and my track record kind of proves my point.
He needs time and he thinks he's not ready for a relationship. <br />
If he's the kind of guy who can be very thoughtful, shy, ... Then chances are that he has a low self-esteem and that he considers you out of his league and that he doesn't deserve you.<br />
Other than that, he might be telling you in a polite way that it's best to stay friends for the time being.<br />
All I can say is that time will tell ...
he has no or little confidence...he feels he has nothing going for him...
If it was up for discussion, you should have asked why. Hit him up again.
He has LOW SELF ESTEEM.
There is a problem?