In its latest update, the general staff of the Ukrainian Armed Forces says Russian preparations continue in the east for an offensive operation, with command and control as well as aviation being added to the gathering force.
It says Russia is training additional units of its Southern Military District "to conduct hostilities" in Ukraine and claims Russia is planning an additional mobilization nationwide.
"The enemy continues to launch missile and bomb attacks on infrastructure facilities and residential areas of cities and villages," the general staff says.
At the same time the Russian armed forces are "regrouping units in the northern direction with a further concentration in areas bordering Ukraine. From the Bryansk and Kursk regions, there is a movement to Russia's Belgorod and Voronezh regions."
The General Staff says Russian units inside Ukraine are conducting reconnaissance in areas such as Slobozhansky in Kharkiv region ahead of the planned offensive, while the shelling of Kharkiv city continues. It says they are also preparing for offensive action towards Slaviansk, an important town in Donetsk region.
Fighting continues in towns around Severodonetsk, the General Staff says. The Russians had tried to break through Ukrainian defenses in the region but had failed.
Civilians continue to be evacuated from the region, which has seen weeks of shelling as the Russian invasion of Ukraine has shifted to seizing control of the eastern regions of Donetsk and Luhansk.
Serhii Haidai, head of the Luhansk region military administration, said Thursday that despite the opening of humanitarian corridors the Russians continued to shell the cities of Luhansk region throughout the day.
Pavlo Kyrylenko, head of the Donetsk region military administration, said the Russians had carried out three air strikes on the town of Velyka Novosilka, close to the border between Donetsk and Zaporizhzhia.
At least two people had been injured, he said. And further north, in Zarichne, one person was killed in Russian shelling. In Vuhledar on the frontlines in Donetsk region, one person had been killed, but a further 46 people had been evacuated from the town, Kyrylenko said.
"I once again call on all those who are not involved in the work of critical infrastructure to leave the region as soon as possible," he said.
The military landscape in eastern Ukraine shows a three-pronged offensive taking shape - with Russian forces edging forward from the north, east and south but meeting stiff resistance on all fronts.