Russia says its forces have managed to capture more territory in the heavily contested city of Bakhmut in the Donetsk region.
Russia's defense ministry said in a statement on Sunday that troops secured two more blocks in Bakhmut's western districts and that airborne units were providing reinforcements to the north and south.
Yevgeny Prigozhin, head of the private Wagner military force, also said his troops control 80% of Bakhmut.
The battle over the city has been dragging on for months.
Ukraine has already acknowledged that Russian forces had made some advances in fierce fighting for Bakhmut but still alleged that the situation was under control.
In another development on Sunday, the Russian-installed head of Ukraine's southern Kherson region denied reports that Ukrainian forces had taken up positions on the eastern bank of the Dnipro River.
"There is no enemy foothold on the left (eastern) bank of the Dnipro river ... our military completely controls that territory," Vladimir Saldo wrote on his Telegram channel.
“There may be cases of enemy sabotage groups making landings to take a selfie, before being ... destroyed or pushed into the water by our fighters," he wrote.
A US-based think tank, the Institute for the Study of War, claimed that Ukraine had "established positions" on the eastern bank, though it was not clear "at what scale or with what intentions."
Russia withdrew its forces from the western bank of the river in November last year, but it still controls large parts of Kherson Oblast on the other side of the river.
South of the Kherson region is Crimea, which Russia seized in 2014
Russia has been carrying out what it calls a special military operation against Ukraine since last February. Moscow says the operation aims to stop Kiev's persecution of the pro-Russian population in eastern Ukraine and to "de-Nazify" the ex-Soviet republic.