A black belt in judo（柔道） , he will be watching bouts at the Olympic Games on Thursday.

 

He is a former St Petersburg judo champion and has previously released a video to promote the sport. 

 

Mr Putin will also meet Prime Minister David Cameron for talks at Downing Street about the conflict in Syria. 

 

Mr Putin's spokesman said the Russian president would defend what he called Moscow's well argued, consistent and absolutely clear position. 

 

This is Mr Putin's first visit to London for nine years - the last time was for a state visit in June 2003. He was last in Britain for the Gleneagles G8 summit in July 2005.

 

Daniel Sandford, the BBC's Moscow correspondent, says Mr Putin arrives at a time of political upheaval in his own country. 

 

Although he won the presidential election in March for a third time, he had to endure the biggest street protests in Moscow since the early 1990s as opposition groups accused him of rigging the vote, our correspondent added. 

 

Since then there has been a clampdown on the opposition, with some activists ending up in prison. Three women from the anti-Putin punk group Pussy Riot are also standing trial this week, after being arrested for performing a protest song against Mr Putin at Moscow's Christ the Saviour Cathedral. 

 

 

His political talks with Mr Cameron will come two weeks after Russia and China vetoed the latest UN attempt to end the fighting in Syria, as government forces continue to battle to regain full control of the country's biggest city, Aleppo.

 

Repeated efforts for a new UN resolution have failed following Russia's backing for President Assad.

 

One of President Putin's advisers told the BBC that the international community's support for opposition forces in Syria was "irrational and irresponsible".

 

Meanwhile, UN relief co-ordinator Baroness Amos has claimed the lack of an established safe zone in Syria is hampering（妨碍，束缚） attempts to help civilians caught up in the fighting.

 

"What we need first of all is a ceasefire, which we have not been able to get, so people can be safe," said Lady Amos. 

 

"Without that, some kind of corridor or safe zone of course would be something we could look at if we could make it secure.