As presidential portraits go, it's a little on the informal side.

Vladimir Putin poses stripped to the waist, fishing rod in hand, in a boat on a Siberian river.

The Russian leader has been worrying Western leaders by flexing his political muscles. But this week, the 54-year-old former KGB officer and fitness nut was showing off the real thing.

Wearing only combat trousers tied roughly at the waist, a camouflage hat and army-style boots, Putin displayed his usual ice-cold expression as he waited for the fish to bite on the Yenisei River on both Monday and Wednesday.

Putin is playing host to Prince Albert of Monaco, a thank you for the latter's support of Russia's successful bid for the 2014 Winter Olympics.