Bashar Assad
Bashar AssadReuters

Syrian President Bashar al-Assad has congratulated Iran on the nuclear deal struck with the European Union (EU) and P5+1 powers Tuesday, Syrian state news agency SANA said Tuesday. 

In a message to Iran's supreme leader Ayatollah Ali Khamenei, Assad congratulated Tehran on a deal he said would be a "major turning point in the history of Iran, the region and the world." 

Iran is the key backer and ally of Assad and has provided him with military support during his fight against rebels trying to topple his regime.

Former Iranian President Mahmoud Ahmadinejad personally sanctioned the dispatch of officers from the Iranian Revolutionary Guards to Syria to fight alongside Assad’s troops. The Islamic Republic’s current President, Hassan Rouhani, has said Tehran will back Assad "until the end of the road."

Last week, Assad signed a law ratifying a $1 billion credit line from Iran to war-torn Syria. The money allegedly would be used for funding imports of goods and commodities and implementing project, state media said. 

Tehran's financial aid has been seen as pivotal to the Syrian government and the economy, which has shrunk by more than a half in the four years since the conflict erupted, researchers say.

AFP contributed to this report.