When to move kid to briefs (pants)?

my 4 year old Is potty trained, I have put him in pants numerous times, but every time he will just cry until there taken off and putt back in nappies, he never really moved to pull ups because he did not like them either. Should I just put him in them and  keep him in them? I tried that once and he just used them as a toilet all day, even after changing.

What should I dooo?