McCarthy wants to reward Mings after rejecting a deadline-day bid from Crystal Palace.
"We have discussed the possibility - rather the certainty, I should say - of giving Tyrone a new contract and that will be the case," McCarthy told the club's official website.
"That is the reward for getting in the team and doing well.
"Neither (owner) Marcus Evans nor I wanted him to go. We want him here for the long term.
"I want to keep my best players. I want to keep the young, exciting players and Ty is one of them."
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