The official, who requested anonymity as they were not allowed to brief the media, told AFP “Sharaa will ask the Russian president to hand over all individuals who committed war crimes and are in Russia, most notably Bashar al-Assad.”

The longtime ruler, who was toppled in December, sought refuge in Moscow.

Syria’s state news agency SANA said Sharaa arrived in Russia on Wednesday for “an official visit to hold talks with his Russian counterpart, Vladimir Putin, on bilateral relations between the two countries and regional and international developments of common interest”.

The official had told AFP on Tuesday that Sharaa and Putin would also discuss “economic issues related to investment, the status of Russian bases in Syria, and the issue of rearming the new Syrian military”.

Russia was a key ally of Assad during the 14-year Syrian civil war.

After providing him with diplomatic support at the UN Security Council, it intervened militarily to support Assad in 2015 with heavy air bombardments of rebel-held areas.

Despite this, Syria’s new Islamist rulers have sought peaceful relations with Russia.

Uncertainty has clouded the fate of Russia’s naval base in Tartus and its air base at Hmeimim since Assad’s ouster.