G8 leaders are in Northern Ireland for a summit set to be dominated by the conflict in Syria.
British Prime Minister David Cameron said he hopes they will focus on finding 'common ground' on the issue of bringing peace.
But Russia opposes plans by the United States to arm the rebels and will not allow a no-fly zone to be imposed over Syria.
The two-day summit is also expected to focus on global economic issues.
Mr Cameron said a successful agreement would have a greater impact than all other world trade deals put together.
"This is a once-in-a-generation prize and we are determined to seize it," he said.
Canada, France, Germany, Italy, Japan, Russia, the United States and Britain are represented at Lough Erne, County Fermanagh.
The US and EU members of the G8 have announced that talks are to begin on a wide-ranging free trade deal.
Mr Cameron on Monday officially welcomed all the leaders to Lough Erne.
The topic of Syria is set to be discussed at the working dinner on Monday evening.