Please don't force him - ever! Each time you force him to do something against his will, you are damaging the trust between the two of you and it will take evn longer for him to settle and accept you.
Give him time to come to you on his own terms. Spend time with him, talking to him, offering treats, etc. without engaging in physical contact. Visit him in his cage as often as possible, just for a little chat.
Trust me, I have experience with a difficult to win over bird (also a zon) and ALL that works is patience, kindness, love and lots of 'undemanding' attention. He will come around, in time.
What is his name, can we see a pic?