Wait or move on?

How long should you wait on a person that tells you that they like you but aren’t ready for a relationship right now? Do you actually wait or do you move on? I’ve never been in this situation before so I don’t really know what to do.

Update: thanks for replying ladies, I appreciate it. My question is, if I do decide to move on, would it be possible for me to ask him to remain friends? We were friends before we decided to start “talking” to each other and I do want him still in my life. Would it be weird for me to ask if we could be friends instead of dating?