Former senator says marine protected area urgently needed to safeguard the Ross Sea from overfishing.
US Secretary of State John Kerry has backed a US-New Zealand proposal for the world's largest marine reserve in the Antarctic at a special screening of a New Zealand film.
Mr Kerry called for the creation of the huge marine protected area (MPA) in the Ross Sea at the National Geographic Museum in Washington, where Christchurch film-maker Peter Young's documentary The Last Ocean was shown.
He spoke alongside New Zealand Ambassador to the US Mike Moore and Australian Foreign Minister Bob Carr at the event, organised by Pew Environment Group.
"We're proud to join with New Zealand and Australia, two countries that have an extraordinary understanding of the sea and commitment to protecting it and who have been great stewards."
It was the first time the former senator had publicly discussed proposals to protect the Ross Sea from overfishing since replacing Hillary Clinton, who was a strong supporter of conservation in the Antarctic.
He described the Ross Sea as a natural laboratory and stressed the urgency in protecting it: "We're not going to wait for a crisis before we take action. We disrespect it at our peril."
In July, 25 countries with interests in Antarctica will decide whether to establish permanent protection for the region or allow fisheries - including boats from New Zealand - to continue to operate there. An attempt to establish a reserve in November failed after objections from nations with fishing interests.
The new joint US-NZ proposal on the table is a 2.27 million sq km protected area which included a tag-and-release programme on the Ross Sea's continental shelf, where the highest concentration of Antarctic toothfish was found.
Mr Moore noted the scale of the MPA would be nearly nine times the size of New Zealand.
Mr Young, said the MPA proposal was a "great first step" but did not go far enough because it failed to protect the most productive areas.
Mr Kerry said he hoped that The Last Ocean would inspire people to be responsible stewards of "this fragile planet".