Russia began launching cruise missiles into Syria from warships in the Caspian Sea in coordination with Syrian ground troops Wednesday, the BBC reported.
The move marks the first coordinated assault since Russia began its military campaign in Syria on Sept. 30 and is a distinct escalation in Russian involvement in the Syrian conflict, The New York Times reported.
The offensive aims to retake areas that border the government-held Latakia province and are held by rebels. The Syrian Observatory for Human Rights reported that there was intense fighting in the Hama and Idlib provinces, which border Latakia.
Russia has stated its military actions are meant to target “all terrorists.” However, Western officials have argued that the strikes are instead meant to attack forces that are fighting Syrian President Bashar al-Assad, some of whom are backed by the U.S.
The missiles traveled over 930 miles and over Iraq and Iran to reach Syria.
Defense Secretary Ash Carter said Wednesday that the U.S.-led coalition is not cooperating with Russia in its military action, and will not cooperate as long as it strikes the rebel groups, Reuters reported.
The U.S. is currently talking to Russia about how to make sure aircraft steer clear of each other while flying over Syria, a process called “deconfliction,” Carter said.