Prime Minister Anthony Albanese has made a bold declaration about climate change and animal habitat loss during a brief speech to a side event at the United Nations.
In a video message, Mr Albanese said Australia endorsed the Leaders' Pledge for Nature.
The pledge commits to reversing biodiversity loss by 2030, including stopping human-caused extinction of species.
"Australia understands the urgency of the environmental challenges facing our planet, and we're committed to being a leader in the global fight to solving it," he told the event on the sidelines of the 77th UN General Assembly in New York.
The prime minister said Australia's approach to protecting the environment "signals our solidarity with other world leaders in our commitment to taking strong action on the dual crises of biodiversity loss, and climate change".
"Working together we can better protect and conserve the world's land, sea, waterways, and cultural heritage for future generations," Mr Albanese said.
"Now is the time to act."
Mr Albanese said Australia was one of a few "mega diverse" countries on the planet.
Australian Conservation Foundation chief executive Kelly O'Shanassy called on Mr Albanese and Environment Minister Tanya Plibersek to attend the UN's biodiversity COP15 in Montreal in December.
"Australia is failing to meet its international obligations, conservation efforts are hugely underfunded and only 100 of Australia's more than 1900 listed threatened species and communities are prioritised for recovery action," she said.
Foreign Minister Penny Wong is leading Australia's delegation in New York.
Climate Change Minister Chris Bowen is also visiting the US to take part in climate week at the UN, and represent the nation at a clean energy meeting in Pittsburgh.
UN Secretary-General Antonio Guterres has urged Australia and other developed nations to impose a windfall tax on fossil fuel companies.