The United Nations cultural heritage body, UNESCO, urged Australia on Saturday to accelerate efforts to save the Great Barrier Reef, saying long-term targets to improve its health are unlikely to be met.

Progress toward achieving water quality targets has been slow, and Australia is at risk of falling short of its 2050 goals, UNESCO warned in a draft assessment of World Heritage sites prepared ahead of a meeting in Krakow, Poland, in July.

"The World Heritage Centre and IUCN consider that the implementation of the Plan will need to accelerate to ensure that the intermediate and long-term targets of 2050 LTSP (Long-Term Sustainability Plan) are being met, in particular regarding water quality," the report said.