U.S. President Barack Obama will press world leaders at the Group of 20 summit in Russia for backing of a possible U.S. strike on Syria.
Russian President Vladimir Putin announced plans to add Syria to the agenda shortly after summit participants arrived Thursday in St. Petersburg.
In an opening session, Mr. Putin said some leaders had asked him to set aside time to discuss "very acute topics of international politics," in particular Syria. He said talks could take place during Thursday's working dinner.
The Syrian crisis is not on the official agenda for the two-day global economic summit, but Mr. Obama and other leaders have been discussing the issue on the sidelines.
The president is seeking broader support, both at home and abroad, for military strikes against Syria's government for allegedly using chemical weapons on its civilians.