Meeting Putin at the Kremlin, Albert said: "You have very kindly praised my sporting qualities but you yourself, Mr President, are a great sportsman and you would have had no problem in following me and participating in this marvellous adventure".

Putin's sporting prowess is well-documented: he is a black-belt in judo (a souvenir from his days at the KGB) and swims daily. He is also often to be seen on horseback in summer and descending the ski slopes in winter.

Prince Albert, meanwhile, has just completed a four-day trek across the Polar ice-shelf, accompanied only by the Russian explorer Matvei Shparo, the British skier Annabelle Bond, his doctor, four other people, and 36 husky dogs.

He set off on Thursday from the floating Russian weather station of Barneo and reached the Pole on Sunday.

Once there, Albert offered a grim warning on the effects of global warming, which he said were clearly evident at the top of the world.

"I think everyone by their behaviour can make their small contribution to a global and extraordinary effort", said the Prince -- the only serving head of state to visit the North Pole -- before being helicoptered away.

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