Media mogul Rupert Murdoch says he has no regrets about supporting the US-led invasion of Iraq and argues the US death toll in the conflict is "minute" from a historical perspective.

The News Corporation chief was speaking on the eve of US mid-term elections where President George W Bush's Republican Party is tipped to lose seats in part due to a backlash over the war.

"The death toll, certainly of Americans there, by the terms of any previous war are quite minute," Mr Murdoch told reporters at a conference in Tokyo.

"Of course no one likes any death toll, but the war now, at the moment, it's certainly trying to prevent a civil war and to prevent Iraqis killing each other."

Murdoch - whose News Corp empire includes the New York Post, Britain's most widely read newspaper, The Sun tabloid and The Australian - says while the United States has made mistakes in the war, its intentions are good.

"I believe it was right to go in there. I believe that certainly the execution that has followed that has included many mistakes," he said.

"But that's easy to say after the event. It's much easier to criticise the conduct of the war today in the media than it was in previous wars. I'm sure there were great mistakes made in the past, too.

"I think that one forgets that American foreign policy for the whole of the (20th) century saved the world from terrible things three times, for which they certainly got no thanks and for which they never had imperial ambitions at all."

Global warming

Mr Murdoch also says he has had a change of heart on climate change and now believes global action is needed - although not in the form of the US-opposed Kyoto Protocol.

Mr Murdoch has called for a new treaty that is acceptable to all countries and brings in emerging economies.

"I have to admit that, until recently, I was somewhat wary of the warming debate. I believe it is now our responsibility to take the lead on this issue," he said.

"Some of the presumptions about extreme weather, whether it be hurricanes or drought, may seem far-fetched. What is certain is that temperatures have been rising and that we are not entirely sure of the consequences."

"The planet deserves the benefit of the doubt."

He spoke as an international summit got under way in Nairobi to discuss the future of the Kyoto Protocol, the world's most far-reaching environmental treaty, which requires industrialised nations to slash greenhouse gas emissions.

He says UK satellite broadcaster BSkyB, which is run by his son James Murdoch, is moving to be "carbon neutral" - or not contributing any net carbon emissions.

I think Unkie Murdoch took his crazy pills