Try them or try them on

Hi. Please help. Let's say a person and his friend went into a department store and upon entering it, they saw a nice pair of pants. He liked them and his friend thought they were nice, too. But his friend didn't want to buy them, but was wondering if he would. Which one can he say, "Try them" or "Try them on"?

His friend: Do you like them? Try them or Try them on.