SYDNEY (AFP) - Australia insisted on Friday that protecting the Great Barrier Reef was a top priority, but conservation group World Wide Fund for Nature (WWF) said not enough had been done to prevent Unesco from deeming it a world heritage site "in danger".

In June, Unesco demanded decisive action from Australia to protect the world's largest coral reef from a gas and mining boom and increasing coastal development, or risk the embarrassment of seeing it put on the danger list.

The deadline it gave Canberra to outline how it planned to improve management and protection and meet key targets recommended by the World Heritage Committee ran out on Friday.

In releasing its response to Unesco, Environment Minister Tony Burke said the government was "absolutely committed" to protecting the reef.

"We have made substantial progress in addressing the recommendations made by the World Heritage Committee, including agreement to conduct one of the most comprehensive strategic assessments ever undertaken in Australia," he said.

He said the response highlighted Australia's "best practices in marine park management and confirms our willingness to share our expertise with other countries experiencing similar conservation issues".

Mr Burke said Canberra had already invested A$200 million (S$258 million) in a "Reef Rescue" programme and would provide an additional A$800,000 to fight the destructive crown-of-thorns starfish, which is decimating the reef.

He added that assessment reports on future planning were being conducted to determine "where sustainable development can occur, the type of development that will be allowed and the conditions under which development may proceed".

But the WWF, along with the Australian Marine Conservation Society, said Australia had failed to show enough progress.

WWF campaign director Richard Leck said it had kept a scorecard on how the federal government and Queensland state government had responded to the World Heritage Committee's list of recommendations.

"The dismal scores highlight our grave concerns that Unesco is going to have no option but to recommend the reef be put on its unenviable 'List of World Heritage in Danger' - the list of shame," Mr Leck said.

"The impact of that would be felt right throughout Queensland's economy, especially its A$6 billion reef tourism industry. Australia's reputation is on the line."

Australia is riding an unprecedented wave of resources investment due to booming demand from Asia, with hundreds of billions of dollars worth of resource projects in the pipeline.

In June, Unesco said the sheer number and scale of proposals, including liquefied natural gas, tourism and mining projects, could threaten the reef's status.

Declining water quality and climate change were the major issues.