The situation around Mariupol remains a priority for the Ukrainian military-political leadership and diplomats, adviser to the head of the President's Office Oleksiy Arestovych has said.

"The most difficult situation is now in Mariupol, near Mariupol. There, the Russians are simply demolishing the city, erasing it from the face of the earth. Our military there have successes. Yesterday they made another attempt at an armored breakthrough of Mariupol, they took prisoners. …More than 2,500 people have been killed there, according to official reports from the local authorities, as far as I understand. And this is a catastrophe that the world has not properly assessed. Now Ukraine's president made Mariupol, for the third day already, his top priority. Both the head of the President's Office, and the president, and all our diplomats are making great efforts: they are making everyone aware of the catastrophe - everyone, including churches, and international organizations, and leaders of the leading countries of the world," Arestovych said on TV telethon on Monday.

He also said that the humanitarian convoy for Mariupol scheduled for Sunday could not be delivered.

At the same time, about 50 units of Russian equipment, which were part of a convoy of 200 units, were destroyed in the Melitopol area.

"According to preliminary data, verified, more than 50 pieces of equipment were destroyed. Not 200, as first reported – the convoy itself was 200. And when we looked at how much was destroyed – about a quarter, 50. But this is actually a lot," Arestovych said.

He also said that the next round of talks, scheduled for Monday, will be held in video format.