Inside the first line of defense, battles are ongoing, according to Mykhailo Podolyak, an adviser to the head of the Office of the President of Ukraine, in a conversation with Russian journalist Yulia Latynina.

"Not everyone understands what the Surovikin Line (Russian General Sergei Surovikin) means, whether it sounds nice or what the first echelon is. So, let's imagine, deep inside, say, somewhere around a kilometer... at least five, in some areas up to ten kilometers, everything is completely mined," he shared.

The adviser added that after this, there is a multi-layered trench engineering structure with a large number of stationary points, a large number of anti-tank barriers, and so on, which extend inland for 15-20 kilometers.

"In some places, the first line merges with the second echelon - also small minefields that transition into the next, equally deep one. Our guys have entered inside this line on some sections, covering one, two, three kilometers within this line, and I emphasize this again," Podolyak said