A proposal to create a whale sanctuary in the South Atlantic Ocean has been defeated at an International Whaling Commission (IWC) meeting in Brazil.
Japan and several other pro-whaling countries voted against the proposal, causing it to fall short of the two-thirds majority it needed to pass.
Brazil's Environment Minister, whose country proposed the creation of the sanctuary, said he was "disappointed".
Environmental campaigners are outraged at the outcome.
The proposal was backed by 39 countries, with 25 countries voting against, including commercial whaling countries Iceland, Norway and Russia.
But this is not the first time the proposal to build a whale sanctuary in the South Atlantic Ocean has failed.
A similar proposal, tabled by Brazil, was defeated at an IWC meeting in Panama in 2012.
Brazil's Environment Minister Edson Duarte said he would not be deterred by the latest outcome.
"We will work in other meetings of this commission this year to ensure that the sanctuary will finally be created," he said.
The IWC already recognises two whaling sanctuaries - one in the Indian Ocean and the other in the waters of the Southern Ocean around Antarctica.
In 1986 it also agreed to a moratorium on hunting, which eventually became a quasi-permanent ban.
But by using an exception in the ban that allows whaling for scientific purposes, Japan has still killed between 200 and 1,200 whales every year since, including young and pregnant animals.
And Japan is now looking to officially reinstate commercial whaling.
The IWC will later this week give its verdict on whether it will overturn the ban on commercial whaling.
Whaling in the 19th and early 20th Century brought the giant mammals to the brink of extinction.