United States president Barack Obama will go into the wild to get a "crash course in survival techniques" from insect-eating British adventurer Bear Grylls, television producers said.

Mr Obama has left the White House for Alaska, where he hopes to highlight the impact of climate change and test his survival skills alongside Grylls.

Mr Obama will appear on an upcoming episode of Running Wild With Bear Grylls, television network NBC said.

Grylls, a former special air service trooper, has boasted that he has pushed celebrities like New Orleans Saints quarterback Drew Brees and Oscar-winning actress Kate Winslet "beyond their limits".

Tasks they have been given include eating mice, jumping out of planes and crossing desert canyons — activities that the Secret Service would not normally allow the president to tackle.

His appearance on the show, which will air later this year, is just the latest in a series of White House efforts to reach new audiences.

Climate change is a hot-button issue in the US, with many Republicans expressing doubts that human actions are truly influencing temperatures.

By visiting glaciers and vulnerable fishing communities, Mr Obama hopes to put those doubts to bed, as he tries to build support for an international pact to curb warming.

He has called global warming "one of the greatest challenges we face this century".

"What's happening in Alaska is happening to us," Mr Obama said before leaving Washington.

"It's our wake-up call. And as long as I'm president, America will lead the world to meet the threat of climate change before it's too late."

Mr Obama has just imposed, much to the chagrin of his Republican opponents in Congress, strict standards to reduce carbon dioxide emissions from power plants.

US is the second-largest emitter of greenhouse gases behind China and has committed to a reduction of 26-28 per cent of greenhouse gas emissions by 2025 compared to 2005.

Alaska is often just a fuel stop for US presidents headed for Asia. But Mr Obama will spend three days in The Last Frontier and become the first sitting US president to visit the Alaskan Arctic.

Many in Alaska, which became America's 49th state in 1959, fear Mr Obama has forgotten the economic difficulties they face.

Climate change deniers on 'own shrinking island'

At the Global Leadership in the Arctic conference in Anchorage, Mr Obama warned climate change was no longer a problem of the future, but rather a challenge for now and one that would define the next century.

Barack Obama said the climate change threat was urgent. ( AFP: Mandel Ngan )

He said the threat was "urgent and growing" and was not being addressed quick enough.

The challenge "will define the contours of this century more dramatically than any other", the president said.

Mr Obama said politicians who argued climate change was not real were "on their own shrinking island" and said fellow world leaders needed to act or "condemn our children to a world they will no longer have the capacity to repair".

"Any so-called leader who doesn't take this issue seriously or treats it like a joke is not fit to lead," he said.

"The science is stark, it is sharpening, and it proves that this once-distant threat is now very much in the present."

Mr Obama listed a thawing permafrost; warmer, more acidic oceans and rivers; species migration; shoreline erosion and longer bush fire seasons among a litany of problems.

Obama renames Mount McKinley with local name Denali

While visiting Alaska Mr Obama will also meet native leaders after announcing a decision to rename Mount McKinley, the tallest mountain in North America, with local name Denali.

The mountain had been named in 1896 for William McKinley who would become the nation's 25th president.

But local authorities had worked on the change for years, restoring an Alaska native name with deep cultural significance.

The move was met with anger by Mr McKinley's fellow Ohio Republican, John Boehner — the speaker of the House of Representatives.

"There is a reason president McKinley's name has served atop the highest peak in North America for more than 100 years, and that is because it is a testament to his great legacy," Mr Boehner said.

"I'm deeply disappointed in this decision."

AFP