The US-led coalition’s Sept. 17 bombing of Syrian government forces has triggered increasingly tough Iranian rhetoric on the role the United States is playing in Syria.

After meeting with the Syrian ambassador to Iran, Hossein Amir-Abdollahian, the former Iranian deputy foreign minister for Arab and African Affairs who now serves as director general of international affairs in parliament, said Sept. 18, “America’s behavior shows that the United States and its allies are always looking to strengthen terrorist groups in Syria and the announced cease-fire should be regarded in that respect.”

According to the Russian Defense Ministry, US-led coalition airstrikes coming from the direction of the Syrian-Iraq border killed at least 62 Syrian soldiers in the eastern city of Deir ez-Zor.

When the Sept. 10 cease-fire plan was announced by the United States and Russia, Iran welcomed the initiative, saying conflict must be ended through dialogue. The Iranian tone has significantly changed in the aftermath of the unprecedented strike on Syrian forces. On Sept. 18, Foreign Ministry spokesman Bahram Ghasemi said, “This American move, which was concurrent with attacks by the [Islamic State (IS)] terrorist group on the same positions, was in violation of the national sovereignty of the Syrian government and such a move showed that terrorist groups enjoy US support in Syria.”