I'm going to put a slightly different slant on things. It certainly can mean all the things people have said before.
But sometimes, just sometimes, it really does mean 'now isn't the right time'.
And sometimes, just sometimes, with time things change.
That's been my experience with my current boyfriend, where it was push-pull for some time, he would run away, come back, say he wasn't ready, run away, come back etc. It took about a year, during which we both kept going on dates with other people, before he finally really was ready. And since then it's been fine.
That said, although we still haven't had sex (religious reasons), we would never meet without the night ending in a kiss. The physical attraction was very definite on both sides. If that isn't there, it may be less likely.
But it's a long game and may not come to anything - your decision if you want to leave the door open or close it irrevocably. I'd recommend walking away for now anyway - it shows respect for what he has told you and respect matters hugely to men.