EU leaders called on Syria and its allies to immediately stop attacking opposition groups Friday, but refrained from directly blaming Russia.
Moscow has been carrying out airstrikes in Syria since September, in support of President Bashar al-Assad. It has helped government forces seize key territory from rebels.
EU leaders had been presented with the option of calling on Moscow to "stop at once attacking moderate opposition groups," but watered down the language in Brussels late Friday.
Instead, they urged "the Syrian regime and its allies to stop at once attacking non-terrorist opposition groups." The attacks threaten "the prospects for peace" in Syria, benefit the Islamic State extremist group and fuel the refugee crisis.
They also called for the "immediate cessation of aerial bombardments in civilian areas" and for "full, sustained and unimpeded humanitarian access throughout Syria."
The war is estimated to have killed more than 250,000 people and driven more than 11 million from their homes since 2011, according to the United Nations.