Vladimir Putin begins fourth term, to be longest serving Prez since Stalin

Vladimir Putin was sworn in as Russia's president for a fourth term on Monday, extending his almost two-decade rule by another six years at a time of high tension with his Western rivals.

The 65-year-old, in power since 1999, is on course to become the longest-serving Russian leader since Joseph Stalin after his victory in March's elections.

Putin won nearly 77 percent of the vote in polls which his most vocal opponent was banned from running in.

He has promised to use his fourth term to revitalise the country's economy. But he also faces a host of delicate international disputes.

"I consider it my duty and my life's aim to do everything possible for Russia, for its present and for its future," Putin said at Monday's swearing-in ceremony, with his hand on the Russian constitution.

Elite guests lining the red carpet filmed Putin on their smartphones as he arrived for the swearing-in ceremony in the ornate Andreyev Hall, part of the Kremlin palace complex.

The car that brought him to the inauguration was a black Russian-made limousine -- a change from previous ceremonies when he used a Mercedes.