BEIRUT (AP) - Russia and Iran renewed their support for the Syrian government in a flurry of calls on Sunday, saying last week's U.S. missile strike violated Syrian sovereignty but failed to boost the morale of "terror groups" in Syria.

In a phone call with Syrian President Bashar Assad, Iranian President Hassan Rouhani called the strike on Friday a "blatant violation" of Syrian sovereignty, Syrian state media reported. Assad accused the U.S. of trying to boost the morale of "terror groups" in Syria. The government refers to all those fighting against it as terrorists.

A statement carried on the military media arm of Hezbollah condemned the American strike in much stronger language, saying it had "crossed red lines" and vowing to "reply with force" to any future aggression "in a variety of ways."

The Lebanese militant group has invested thousands of fighters in the defense of Assad's government. The statement was made in the name of a previously unheard of "shared operations room" between Russia, Iran and allied forces. There was no comment from Russia or Iran about the statement.

The Kremlin said in a statement Rouhani also spoke with Russian President Vladimir Putin by phone.

"Both sides noted the inadmissibility of aggressive U.S. actions against a sovereign state in violation of international law," the statement said. "Vladimir Putin and Hasan Rouhani spoke in favor of an objective, unbiased investigation of all the circumstances of the chemical weapons incident on April 4 in the Syrian province of Idlib."

Rouhani said the U.S. strike would not affect Iran's Syria policy, while Supreme Leader Ayatollah Ali Khamenei said Iran would not withdraw in the face of similar aggressions.

"What the Americans did is a strategic mistake and offense. They are repeating offense of their predecessors," Khamenei was quoted as saying by the official IRNA news agency.

Iran has provided crucial military and economic assistance to Assad throughout Syria's six-year civil war. It has organized several Shiite militias from around the Middle East to fight in support of Assad's government and has sent troops and officers from its own Revolutionary Guards.

The U.S. says the strike was in response to a nerve gas attack on the rebel-held town of Khan Sheikhoun last week, which has been widely blamed on government forces. The Syrian government has denied using chemical weapons.