A man walks in the rubble near damaged buildings, as Russia's invasion of Ukraine continues, in Bakhmut, Donetsk Oblast, Ukraine in this still image obtained from a social media video released on July 2, 2022. National Police of Ukraine/Handout via REUTER
A man walks in the rubble near damaged buildings, as Russia's invasion of Ukraine continues, in Bakhmut, Donetsk Oblast, Ukraine in this still image obtained from a social media video released on July 2, 2022. National Police of Ukraine/Handout via REUTERS . Reuters / NATIONAL POLICE OF UKRAINE

Russia will shift the main focus of its war in Ukraine to trying to seize all of the Donetsk region after capturing neighbouring Luhansk, the Luhansk region's governor said on Monday.

Governor Serhiy Gaidai told Reuters in an interview that he expected the city of Sloviansk and the town of Bakhmut in particular to come under attack as Russia tries to take full control of what is known as the Donbas in eastern Ukraine.

Russia says it has established full control over the Luhansk region following a withdrawal by Ukrainian forces from the bombed-out city of Lysychansk.

"In terms of the military, it is bad to leave positions, but there is nothing critical (in the loss of Lysychansk). We need to win the war, not the battle for Lysychansk," Gaidai said.

"It hurts a lot, but it's not losing the war."

He said the withdrawal from Lysychansk had been "centralised", indicating that it had been planned and orderly, but that Ukrainian forces had risked being surrounded.

"Still, for them (Russian forces) goal number 1 is the Donetsk region. Sloviansk and Bakhmut will come under attack - Bakhmut has already started being shelled very hard," he said.