President Bashar al-Assad meets Iran’s Supreme Leader’s adviser Ali Akbar Velayati in Damascus on Sunday.

AFP/Damascus

Syrian President Bashar al-Assad said on Sunday that his enemies abroad had increased support for the regime's armed opponents since the start of a major offensive to win back lost territory.

Meeting with a senior Iranian official in Damascus, Assad highlighted "important gains by the Syrian army in the fight against terrorism, with the support of its friends led by Iran and Russia," state news agency SANA reported.

But these gains, he said, have "pushed certain countries hostile to Syria and who pretend to fight terrorism to... increase their financing and arming of terrorist groups."

Since the outbreak of Syria's conflict in 2011 Assad has accused countries including Turkey and Gulf nations of arming his opponents.

Assad's regime, dominated by the Shia Alawite sect, launched a key offensive to retake areas seized by opponents after Moscow launched air strikes in support of the government in late September.

Iran, the region's main Shia power, has also backed Assad, including with the reported deployment of hundreds of "military advisers" to bolster regime forces.

After his talks with Assad, Ali Akbar Velayati, a top adviser to Iran's supreme leader, said Tehran was determined to "continue its support for the Syrian government and people, because the war against terrorism is crucial for the region and the world."

Velayati also praised Iran for its "exceptional resistance" to "terrorists supported by regional and Western countries".

Assad insisted that talk of a political solution to Syria's civil war could only take place after "eradicating terrorism".

"This is the real prelude to the success of any political solution decided by Syrians," he said.

Assad routinely denounces all armed opponents of his regime as "terrorists" regardless of their motives or affiliation.

Syria's conflict broke out in March 2011 initially as an anti-regime uprising but evolved into a multi-front war that sees the regime, jihadists including the Islamic State group, secular rebel forces and a range of ethnic militias battling for territory.

More than 250,000 people have died in the fighting and millions have been forced from their homes.