Zelensky, speaking in an evening video address, also said there would be good news from the front, but gave no details.

The most severe fighting is taking place near Avdiivka, outside Donetsk, and Bakhmut, further to the northeast, he said.

“This is where the craziness of the Russian command is most evident. Day after day, for months, they are driving people to their deaths there, concentrating the highest level of artillery strikes,” he said.

Russian forces have repeatedly tried to seize Bakhmut, which sits on a main road leading to the Ukrainian-held cities of Sloviansk and Kramatorsk.

Zelensky advisor Oleksiy Arestovych said on Tuesday that on one particular day, the Russians had attacked Bakhmut eight times before lunch and been pushed back every time.

Zelensky did not mention what was happening near the southern city of Kherson, which is held by pro-Moscow forces. Ukrainian troops say they expect a tough fight there.

“Generally, we are strengthening our positions all over the frontline, reducing the invaders’ capabilities, destroying their logistics, and preparing good news for Ukraine,” he said.

Separately, Russian-installed authorities in Shakhtarsk, just to the east of Donetsk, said Ukrainian shelling had set ablaze fuel tanks at the town’s railway station.

Ukrainian forces, some equipped with artillery supplied by the US and other allies, have methodically shelled Russian fuel and ammunition bases and railway lines.

Zelensky also said that in the latest prisoner exchange between the two sides, 10 Ukrainians had been freed.