Secretary of State John Kerry in Geneva on Thursday said that talks with Russia to secure Syrian President Bashar Assad’s chemical weapons stockpile are “not a game” and that the U.S. would press Moscow and Damascus to follow through on their promises.

“Expectations are high,” said Kerry at a joint press conference with Russian Foreign Minister Sergey Lavrov as the two began talks on an agreement that would turn over Syria’s chemical weapons arsenal to international inspectors and avert a threatened U.S. strike. “They are high for the United States and for Russia to deliver.”