Ukraine warns of Mariupol's desperate plight ahead of peace talks

Ukraine warned on Monday the humanitarian crisis in the pulverised city of Mariupol was now "catastrophic", as fighting surged around Kyiv ahead of new face-to-face peace talks with Russia in Turkey.

Russian attacks near Kyiv cut power to more than 80,000 homes, officials said, underscoring the peril facing the capital despite an apparent retreat in Moscow's war aims to focus on eastern Ukraine. 

"The enemy is trying to break through the corridor around Kyiv and block transport routes," Ukraine's deputy defence minister Ganna Malyar said. 

"The defence of Kyiv continues. It is very serious today," she said.

"It is extremely difficult for the enemy, but we must be honest about the fact that the enemy is trying to capture Kyiv, because to capture Kyiv is essentially a captured Ukraine, and this is their goal."

About 20,000 Ukrainians have been killed in Russia's month-old invasion and 10 million have fled their homes, according to Kyiv, and several cities are still coming under withering bombardment.

Humanitarian needs are direct in the southern port city of Mariupol, where Ukraine said that about 160,000 civilians remain encircled by Russian forces, desperate for food, water and medicine.

Ukraine's foreign ministry said the situation there was "catastrophic" and Russia's assault from land, sea and air had turned a city once home to 450,000 people "into dust".

Ukraine says that one Russian strike on a theatre-turned-shelter in Mariupol is feared to have killed some 300 people. 

Ukraine decided against any humanitarian corridors on Monday because of potential "provocations" by the Russians along designated routes, Deputy Prime Minister Iryna Vereshchuk said.

France, Greece and Turkey are hoping to launch a mass evacuation of civilians out of Mariupol within days, according to French President Emmanuel Macron, who is seeking agreement from Russia's Vladimir Putin.

Macron warned that any escalation "in words or action" could harm his evacuation efforts, after US President Joe Biden's shock declaration in Poland that Putin "cannot remain in power".