Should I tell my crush I like him before he leaves?

So there this boy I like who's a year older than me and he's leaving to Kuwait next year. I've liked him for a while now but I've never told him how I really feel. He shows signs like he likes me but he's never done anything or acted on them I should say. Basically I just wanna know if I should tell him now or wait till he's about to leave or just not at all. I know this is stupid I just wanna hear other people's opinions. Thanks for the help I really appreciate it. I'm 16 and he's 17 =)