Volodymyr Zelenskiy, the Ukrainian president, has again urged Russia to negotiate an end to war, but also asserted that Ukraine would not agree to give up any of its territory to achieve peace.

The French president, Emmanuel Macron, is trying to assemble an international coalition to evacuate civilians from Mariupol. Macron said France was working with Turkey and Greece on the “humanitarian operation … I will have a new discussion with President Vladimir Putin within the next 48 to 72 hours to work out the details and secure the modalities,” he said.

The US president, Joe Biden, has visited the Polish town of Rzeszów, about an hour’s drive from the Ukrainian border, in a show of support for eastern European states that are seeing Russian aggression wreak havoc in their neighbourhood.

Authorities in Mariupol have said as many as 300 people were killed in a Russian bombing of a theatre last week, putting a death toll for the first time on the deadliest single attack since Moscow launched its invasion.

Western officials have said they believe a Russian commander was run over by mutinous forces during the fighting in Ukraine, in a sign of what they described as the “morale challenges” faced by the invading forces.

Vladimir Putin has accused the west of discriminating against Russian culture, comparing the treatment of Russian cultural figures to that of the “cancelled” Harry Potter author JK Rowling.

The Russian president on Friday signed into law a bill introducing jail terms of up to 15 years for publishing what the Kremlin deems “fake” information about any of Russia’s actions abroad.

Russia’s defence ministry said on Friday that the first phase of its military operation was “generally” complete, and it would focus on the “liberation” of Ukraine’s eastern Donbas region. US officials were cautious about whether this meant the Kremlin was scaling back its overall objectives amid a haphazard war campaign.