Top diplomats from the United States and Russia have failed to reach a deal to ease fighting in Syria.
A senior U.S. State Department official said on September 5 that talks between U.S. Secretary of State John Kerry and Russian Foreign Minister Sergei Lavrov on the margins of the G20 summit in Hangzhou had ended without agreement.
Kerry and Lavrov have been in talks for weeks over a deal to boost U.S. and Russian military cooperation to fight the Islamic State group and other extremists in Syria.
A possible deal could include provisions to ensure aid can reach besieged areas of Syria and steps to prevent Syrian President Bashar al-Assad's government from bombing areas where U.S.-backed rebels are operating.
The civil war has killed more than 250,000 people and displaced 11 million, causing a refugee crisis in the Middle East and Europe and contributing to a rise in militant Islamist groups.
Russia has backed Assad, but the United States has worked with moderate opposition forces fighting Assad.