US Secretary of State Hillary Clinton has urged tighter controls on cruise ships and tourists in Antarctica to prevent further environmental damage.
Addressing an international meeting on both the Antarctic and the Arctic, Mrs Clinton said as tourism increases to Antarctica there must be more regulations governing that travel.
She said the US has proposed limits on landings from ships carrying large numbers of tourists, and new requirements for lifeboats on tour ships to make sure they can keep passengers alive until rescue comes.
Tourism to the Antarctic region has increased five-fold since the early 1990s as tens of thousands of people cruise during the Southern Hemisphere's summer to see shrinking icebergs and wildlife.
In the past four months, there have been two rescue efforts for cruise ships stranded in icy Antarctic waters. Over a year ago, more than 150 crew and passengers escaped in a dramatic rescue after their ship hit ice off Antarctica and sank.
Hillary Clinton also said more needed to be done to prevent further degradation of the environment around Antarctica caused by vessels going to the region.
There have been concerns over shipwrecks, oil spills and aggravation of stresses on animals and plants that may already be suffering from global warming.
The Obama administration has made tackling climate change a priority and Mrs Clinton said the urgency of the issue was reflected by the collapse last weekend of an ice bridge holding together a huge Antarctic shelf.
Mrs Clinton was speaking at a joint session of the Antarctic Treaty Consultative Meeting and the Arctic Council.
