(Adds Kerry quotes)
THE HAGUE, March 24 (Reuters) - U.S. Secretary of State John Kerry said on Monday he hoped the Crimea crisis would not harm cooperation with Russia on international efforts to destroy Syria's chemical weapons.
Syrian President Bashar al-Assad's government agreed to destroy its chemical weapons arsenal as part of a U.S.-Russian agreement negotiated after a chemical attack last August that killed hundreds of people around Damascus.
"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 was due to attend a summit of the G7 leading industrialised nations.
"This is bigger than either of our countries. This is a global challenge," Kerry said.
Syria has missed almost all deadlines agreed in the deal brokered by Kerry and his Russian counterpart Sergei Lavrov, whom he is due to meet for bilateral talks in The Hague. Syria is several weeks behind schedule in handing over its toxic stockpile.
Plans for a joint mission between Russia and NATO to protect a U.S. cargo ship that will destroy Syria's deadliest chemical weapons have been cancelled amid increased tensions over Russia's annexation of the Crimea.
Kerry, who made no further allusion to Crimea in his remarks, noted that the Syrians had also missed a March 15 date for destruction of a dozen production and storage facilities.
"We have some real challenges ahead of us in these next weeks. We in the United States are convinced that if Syria wanted to they could move faster," he added.
Kerry confirmed that about half of Syria's declared chemical weapons arsenal has been shipped out or destroyed within the country.
"We are just about at the 50 percent removal mark. That is significant but the real significance would only be when we get all the weapons out," he said.
Kerry was speaking at the Organisation for the Prohibition of Chemical Weapons (OPCW), which won the Nobel Peace prize last year, and was also due to meet the OPCW's Turkish head, Ahmet Uzumcu. (Reporting by Fredrik Dahl, Writing by Geert De Clercq; Editing by Gareth Jones)