The leaders of Britain, Canada, France, Germany, Italy, Japan and the United States met at the Dutch prime minister's residence in The Hague on the sidelines of a nuclear security summit, an AFP correspondent said.
European Commission President Jose Manuel Barroso and European President Herman Van Rompuy also attended the talks, held around a small circular table with the flags of the countries behind the leaders.
The G7 leaders will attempt to agree on possible further punishment of Russia for its annexation of Crimea, with British Prime Minister David Cameron saying that Moscow would already see its planned G8 meeting boycotted.
The G7 meeting, called by Obama in response to the worst East-West confrontation since the end of the Cold War, was being held on the sidelines of a major nuclear security summit in The Hague, which wraps up tomorrow.
