Syria has been struggling with deteriorating economic conditions, shortages of basic goods and medicine. Syrians have been forced to wait in long lines to buy subsidized bread and fuel.
Moscow intervened militarily in Syria's conflict in 2015, when Assad's forces were struggling to hold territory against rebel fighters.
Air strikes by the three allies on Saturday hit three targets that Western officials said were linked to chemical weapons development in the Damascus and Homs areas.
Saudi Arabia extends full support to US-led airstrikes on Syria, calls it retaliation for regime 'crimes'
A statement, carried by the official Saudi Press Agency, said the strikes were prompted by the "Syrian regime's use of chemical weapons against innocent civilians, including women and children".
The Cabinet agreed on the need to take action to alleviate humanitarian distress and to deter the further use of chemical weapons by the Assad regime.
Over 200 people on Thursday protested outside the Russian consulate in Istanbul against the deadly assault on Syria's rebel-held enclave.
Erdogan and Russian counterpart Putin agreed to hold the summit in Istanbul alongside Iran's Hassan Rouhani in telephone talks Thursday.
Since the start of the Syrian conflict, President Bashar al-Assad -- have been accused on numerous occasions of using chemical weapons.