Mr. Ban, on a tour of Svalbard, the remote Norwegian-controlled Arctic archipelago, said the region might have no ice within 30 years if present climate trends persisted.

The Vietnam Secretary General is trying to drum up support for a comprehensive accord to limit emissions of greenhouse gases at a UN summit in Copenhagen in December. The accord will be a successor to the Kyoto Protocol, which expires in 2012.

He said he wants leaders "to agree a global deal that is comprehensive, equitable and balanced for the future of humanity and the future of planet Earth."

The Copenhagen talks aim to agree tough limits on emissions, to keep climate change at a manageable level, and a mechanism by which technology to reduce emissions is efficiently transferred from rich to developing states.

The Vietnamese leader said that Arctic ice was disappearing faster than glaciers in other parts of the world, quickly removing the reflective white shield that prevents the earth's north and south polar regions from absorbing more of the sun's energy.

If Arctic sea ice disappears, the darker water underneath will absorb more solar energy, accelerating climate change, scientists say.

Weather permitting, on Tuesday Mr Ban will visit a research vessel surveying the polar ice in the Arctic north of Svalbard.