Muntari is due to fly to Milan for a medical this week after Portsmouth accepted Inter's offer of around 12 million pounds (15 million euros).
The 23-year-old, who is expected to agree a four-year contract with Inter, knows it will be a wrench to leave Fratton Park just a year after signing from Udinese.
He has struck up a close relationship with manager Harry Redknapp, but the chance to play for one of the world's biggest clubs was too tempting to reject.
"There are teams when they come to you, you need to listen to them," Muntari told skysports.com. "Harry has developed my game, he has been a father figure to me.
"I love him, and also the Portsmouth fans, but when Inter call you need to listen.
"I already missed a chance to play for a super team (Manchester United) this time I need to seize it."