US Secretary of State John Kerry said on Monday he hoped the Crimea situation would not impact cooperation with Russia on international efforts to destroy Syria's chemical weapons.

"I hope not. All I can say is I hope the same motivations that drove Russia to be a partner in this effort will still exist," Kerry told reporters in the Hague, where he is planning to attend a G7 summit.

Syrian President Bashar al-Assad's government agreed to destroy its chemical weapons arsenal after a chemical attack killed hundreds of people around Damascus last year.