Moscow was ready to put its nuclear forces on alert to ensure Russia's annexation of Crimea from Ukraine last year, President Vladimir Putin said in a pre-recorded documentary aired on Sunday.
U.S. Secretary of State John Kerry said the United States would have to negotiate with Syrian President Bashar al-Assad for a political transition in Syria and was exploring ways with other countries to pressure him into agreeing to talks.
Ukraine's president accused Russian-backed separatists in the east of failing to respect a ceasefire with Ukrainian troops and called for further sanctions on Russia in comments to a German newspaper to be published on Monday.
Iraqi Kurdish authorities said on Saturday they had evidence that Islamic State had used chlorine gas as a chemical weapon against their peshmerga fighters in northern Iraq in January.
