At a media conference, Tonga's Prime Minister Hu'akavameiliku Siaosi Sovaleni announced Australia would provide technical and financial support for the airline.
Hu'akavameiliku also rebutted media criticism of Lulutai management.
He said management acted quickly when finding out the aircraft was in a state of disrepair.
"When the report came out, it was something we need to address on the plane, it was sent to the manufacturer, and they said the next day to ground the plane, we ground the plane.
