The Syrian army's breaking of a years-long siege by the Islamic State group of Deir Ezzor city is a "very important strategic victory," Kremlin spokesman Dmitry Peskov said Tuesday.

"Commander-in-chief Vladimir Putin has congratulated the Russian military (in Syria) as well as the command of the Syrian government troops with this very important strategic victory over the terrorists with the aim of freeing Syria from ISIL," Peskov told journalists.