Russian President Vladimir Putin on Friday ratified a law sanctioning the country's deal with Syria, which allows Moscow to deploy its forces for an indefinite period in the war-torn nation and set up its Hmeimim airbase permanently to launch attacks on rebels. The agreement, which was signed in August 2015, also protects Russian forces from prosecution in Syria, reported AFP.

Although several countries have criticised Syria's offensive against rebels, its campaign has had backing from Russia. Both nations have been accused of war crimes in the region, and Russia's ratification of the deal is likely to draw more criticism from the West. Foreign ministers of the European Union's member states have also drafted a statement on the alleged war crimes. In addition to several dozen warplanes, Moscow currently has around 4,000 personnel stationed at the Hmeimim airbase in the southeast city of Latakia.

Rescue workers said that more than 150 people have been killed in Syrian military attacks, backed by Russian warplanes, in Aleppo this week. At least 99 civilians died on Wednesday and Thursday alone, reported Al Jazeera. In the last six years, more than 3,00,000 people have died in the civil war in the country.

The ratification of the deal comes a day after Syrian President Bashar al-Assad had said that victory in Aleppo will help his government free other areas of the country from "terrorists". Assad had also said that recapturing Aleppo back from the rebels would be a political and strategic victory for his regime, even though it is no longer Syria's industrial capital.