Russian Foreign Minister Sergei Lavrov told U.S. Secretary of State John Kerry in a phone conversation on April 1 that militants are still crossing from Turkey into Syria, Russia's foreign ministry said.
"Lavrov once again drew attention to the Turkey-Syria border which still has holes and, according to our data, is actively being used to transfer militants via Turkey to Syria," the ministry said.
Lavrov last month called for full implementation of United Nations Security Council resolutions demanding a halt to trade in oil with the Islamic State group and an end to "terrorists" crossing into Syria from Turkey and other countries.
In the phone conversation, the foreign ministry said the two top diplomats also discussed taking "concrete measures aimed at strengthening the ceasefire process in Syria," which was established in late February and has generally been holding.