The Pacific Aviation Safety Office says that nothing wrong has been identified with Tonga's controversial MA60 aircraft except it needs to pass proper type certification.
Flights by the MA60, which was gifted to Tonga by China, have been suspended until it passes aviation standards under Tonga's new legislation.
New Zealand's foreign minister, Murray McCully, was strongly opposed to the plane's operation and his government had issued a travel advisory encouraging New Zealanders not to use it.
Now under new legislation Tonga has formally adopted New Zealand Civil Aviation rules as the standard to which airlines must operate.
The Safety Office's acting senior co-ordinator Robert McLennon says the MA60 is a first of its type in Tonga and needs to undergo the appropriate acceptance certification process.
"So nobody has identified anything wrong with the aircraft, it just needs to go through this formal process before it can operate in the manner that other aircraft are operating in at the moment."
Robert McLennon says his office is working with the Tongan government to establish a process to move forward.