Fonua-Blake, who made his NRL debut for the Sea Eagles in 2016, has added two more years to his current deal.

The Tongan international played in all 24 matches for Manly this season and averaged 126 metres per game.

Sea Eagles coach Des Halser was pleased to lock down the 23-year prop.

"It's a wonderful signing for our club," he said.

"Addin can become one of the great Manly Warringah Sea Eagles front-rowers in its history. This is something that Addin has really worked hard for. The most pleasing aspect is that he has a great appreciation of how he has got there and he understands it."

Fonau-Blake has scored five tries in 60 NRL appearances.