The Tongan Tourism Ministry in New Zealand says it expects the kingdom will make millions from the coronation ceremony of the new king.
The crowning ceremony in August will be attended by visiting heads of state.
But there has been some criticism over the kingdom spending more than three million US dollars on the celebration.
A spokesperson for the Tongan Tourism Ministry in Auckland, Will Ilolahia, is defending the plans, saying he expects the kingdom will earn about 7.6 million US dollars as a result of the event.
"That's based on the amount of money that could be coming into the country through remittances, through donations, through the tourism, people coming just to be there."
Will Ilolahia says airlines are also planning to offer more flights for the occasion.