Britain's Prime Minister David Cameron (L) and Russia's President Vladimir Putin hold a joint news conference in 10 Downing Street, central London June 16, 2013.[Photo/Agencies]

LOUGH ERNE, Northern Ireland - US President Barack Obama will seek the help on Monday of Russia's Vladimir Putin to bring Syria's Bashar al-Assad to the negotiating table and end a two-year civil war.

At their first private face-to-face meeting in a year, Obama will try to find common ground with Putin on the sidelines of a G8 summit in Northern Ireland after angering the Kremlin by authorising US military support for the Syrian president's opponents.

During talks with British Prime Minister David Cameron in London on the eve of the summit, Putin renewed his criticism of the West's position in startling tones, describing Assad's foes as cannibals.

"I think you will not deny that one does not really need to support the people who not only kill their enemies, but open up their bodies, eat their intestines, in front of the public and cameras," Putin said at a joint news conference with Cameron.

"Are these the people you want to support? Is it them who you want to supply with weapons?"

Cameron conceded London and Moscow remained far apart.

Russia does not buy the West's assertion that Assad's forces have used chemical weapons and crossed a red line in doing so, saying US military support for Syrian rebels would only escalate violence.

Washington said on Saturday it would keep F-16 fighters and Patriot missiles in Jordan at Amman's request, prompting Moscow to bristle at the possibility they could be used to enforce a no-fly zone inside Syria. 

Putin appeared upbeat in London, stressing several areas of cooperation between Russian and Britain.

At the Lough Erne golf resort in Northern Ireland, Cameron will bring together leaders of the United States, Japan, Canada, Russia, Germany, France and Italy - representing just over half of the $71.7 trillion global economy.

Syria will inevitably dominate the Monday-Tuesday talks but persistent worries about the global economy will also be central to the discussions.

Market turmoil to focus minds

Japanese Prime Minister Shinzo Abe, German Chancellor Angela Merkel and other leaders will likely discuss the role of central banks and monetary policy.

They are likely to say they are not content with progress so far in fixing their economies in the wake of the global financial crisis, according to a draft communique seen by Reuters.

Japan's Abe will use the opportunity to explain his cocktail of fiscal and monetary stimulus known as 'Abenomics' to the leaders as investors try to absorb the implications of a signal by the US Federal Reserve that it may start to slow its money-printing.

Fed chairman Ben Bernanke will not attend. He and his colleagues hold a two-day policy meeting on Tuesday and Wednesday.

Bond yields have climbed and share prices have sagged globally since Bernanke shocked investors on May 22 by saying the bank might 'take a step down' in the pace of bond purchases - a blow to a global economy still growing well below trend due to the after effects of the great financial crisis.

"Japan's decisive moves to reflate its economy will support growth in the near term, but it will need to manage the twin challenge of providing near-term stimulus and achieving longer-term sustainability," the draft communique said, although the version circulated by Britain and seen by Reuters was put together before the recent market turmoil.

The leaders of the European Union and United States are likely to announce the start of formal negotiations on a free trade deal that could be worth more than $100 billion a year to each economy.

EU and US negotiators aim to finish their work by the end of next year.