He might say he wants to stay friends but then doesn't act accordingly.
Look at his actions, rather than what he says. His actions speak louder than his words.
So, if he sends you one text message a week, that tells you exactly how much time and energy he wants to invest in a friendship with you right now.
My advice?
Invest less or the same as what he does, certainly not more or you will end up losing yourself and getting deeply frustrated.