Russia has banned the hunting of polar bears this year, thanks to a group with close ties to Prime Minister Vladimir Putin, a long-time defender of large endangered animals.

A Russian-US commission last year agreed to restrict polar bear hunting to 29 animals per year for each country.

But The Polar Bear programme, established under Putin's patronage, said Russia had waived its quota for bear hunting.

Although the polar bear is an endangered animal, officials in Russia and the US have said hunting is vital for the indigenous people in Alaska and in far-eastern Russia across the Bering Strait.

The Polar Bear programme, which said US officials had long been reluctant to introduce the cap on hunting, said around 100 polar bears a year have been killed in Alaska in recent years.

"Measures taken by Russia will ensure that the United States will be killing at least 70 polar bears fewer than before, which, according to Russian specialists, will help to sustain and boost the population of this beautiful Arctic animal," the group said in a statement posted on Putin's official website.

Putin last year helped scientists put a tracking collar on a sedated male polar bear. Before leaving the bear, he patted the animal affectionately, shook his paw and said "take care".

He also joined scientists last year in studying the grey whale off Russia's Pacific Coast, firing darts from a crossbow to collect skin samples from a whale swimming near their small boat.

Putin also has championed the cause of endangered big cats. In 2008, he was given a two-month-old female Siberian tiger cub for his birthday, which he later gave to a zoo in southern Russia.

In 2009, he supervised the release of two Persian leopards into a wildlife sanctuary near the southern resort of Sochi, fulfilling his pledge to reintroduce the big cats to the Caucasus region if Russia won the right to hold the 2014 Winter Games.