Three Russian warships crossed Turkey’s Bosphorus Strait Thursday en route to the eastern Mediterranean, near the Syrian coast, amid concern in the region over potential US-led strikes in response to the Damascus regime’s alleged use of chemical weapons.

Russian President Vladimir Putin discussed the situation in Syria with British Prime Minister David Cameron early on Friday, Putin’s spokesman said. Cameron and Putin met on the sidelines of the G20 summit in Saint Petersburg

G20 leaders remain divided over the Syrian conflict as they enter the final day of their Russian summit. The splits were confirmed by both Italian Prime Minister Enrico Letta and US envoy to the United Nations Samantha Power.