You should have settled the matter of mahr at the time of nikah or before it. When you accepted the nikah on the said mahr and signed the nikahnama, that mahr became due on you. If you have met your wife in privacy or have intercourse with her, you will have to pay full mahr. If your wife withdraws her right of mahr happily without any compulsion, it shall be remitted; otherwise, it is wajib on husband to pay it. Talaq is disliked in Shariah; therefore one should not give talaq to his wife except in inevitable circumstances.
Allah (Subhana Wa Ta’ala) knows Best
Darul Uloom Deoband