Russia has named a new commander for its operations in Ukraine, refocusing its war effort in the east after failing to take territory surrounding Kyiv, the country’s capital.

According to Western security officials and diplomats with knowledge of the shift, General Alexander Dvornikov, commander of the Southern Military District, would now head Russian forces on the ground. The appointment has yet to be declared by the Kremlin.

Dvornikov, 60, has served in the Russian military in a number of top capacities, including army commander of the Far Eastern Military District. In 2015 and 2016, he was in charge of Russia’s soldiers in Syria, where they fought with Syrian government troops in a conflict in which President Bashar al-Assad was accused of deploying chemical weapons against his own people.

Russia has mainly withdrawn its forces from the north, with the war now in its seventh week, after encountering heavy resistance and becoming stranded outside Kyiv. Ukraine’s missile attacks also cost Moscow a number of tanks and planes.

Moscow is now concentrating its efforts in the eastern Donbass regions, capturing towns and cities along the Black Sea, notably Mariupol, which has been under siege for weeks. This would allow Ukraine to build a land bridge between Crimea and Russia, which it annexed in 2014.