KYIV: Ukraine warned on Monday the humanitarian crisis in the pulverized city of Mariupol was now "catastrophic", with thousands dead, as fighting surged around Kyiv ahead of new face-to-face peace talks with Russia in Turkey.
A senior Ukrainian official told AFP Monday that around 5,000 people have been buried in the besieged city of Mariupol.
But the burials stopped 10 days ago because of continued shelling," Tetyana Lomakina, a presidential adviser now in charge of humanitarian corridors, told AFP by phone, adding that as many as 10,000 people may have died since the start of the Russian invasion.
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.
"To capture Kyiv is essentially a captured Ukraine, and this is their goal."
UN chief Antonio Guterres said Monday the global body is seeking a humanitarian ceasefire between Russia and Ukraine, as the civilian toll continues to rise a month after Moscow's invasion of its neighbour.
Guterres told reporters he had asked UN humanitarian chief Martin Griffiths "immediately to explore with the parties involved the possible agreements and arrangements for a humanitarian ceasefire in Ukraine."
He said he hoped Griffiths would go to both Moscow and Kyiv as soon as possible after he returns from a mission to Afghanistan.
20,000 Ukrainians killed
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.
Ukraine Prosecutor General Iryna Venediktova said Monday there was proof that Russian forces have used banned cluster bombs in the southern Odessa and Kherson areas.
Humanitarian needs are direst 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".
The Ukrainian government also estimated Monday that the economic damage from the Russian invasion had reached nearly $565 billion, including immediate damage plus expected losses in trade and economic activity.
Ukraine says that one Russian strike on a theatre-turned-shelter in Mariupol is feared to have killed some 300 people.
Unburied bodies line streets and residents cowering in basement shelters have been forced to eat snow to stay hydrated, local lawmaker Kateryna Sukhomlynova told AFP.
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".
Biden himself rowed back on Sunday, denying to reporters that he had been calling for regime change. He said Monday the remark was personal "outrage," not policy.
On Monday he also announced that United States will allocate billions of dollars in aid to Ukraine, tax the wealthy and lower its deficit under a budget proposal President Joe Biden unveiled on Monday.
His budget proposals, which must be approved by Congress, include a $6.9 billion infusion of funding for Ukraine to assist in defending against Russia's invasion, as well as to aid NATO. Another $1 billion would go towards Washington's efforts to counter Moscow's influence.
Peace 'without delay'
Russia has de-facto control over the southern peninsula of Crimea that it annexed in 2014, and the self-proclaimed republics of Donetsk and Lugansk in the eastern Donbas region.
In the Lugansk city of Rubizhne, one person was killed and another wounded by overnight Russian bombardment, according to regional Ukrainian officials.
But Ukrainian forces on Monday recaptured Mala Rogan, a small village on the outskirts of Ukraine's second-largest city Kharkiv in the northeast.
"There are Russian corpses all over the place," a Ukrainian soldier told AFP, who said more than two dozen soldiers dispatched to Ukraine by Moscow had been killed in the fight for the hamlet.
President Volodymyr Zelensky said the first round of in-person talks since March 10 -- due to open in Istanbul on Tuesday after near-daily video contacts -- must bring peace "without delay".
Ukrainian "neutrality", and the future status of Donbas, could be in the mix for the Istanbul meeting. Ukraine's delegation said it had been delayed and the talks would open on Tuesday.
"We understand that it is impossible to liberate all territory by force, that would mean World War III, I fully understand and realise that," Zelensky said.
But he stressed: "Ukraine's sovereignty and territorial integrity are beyond doubt. Effective security guarantees for our state are mandatory."
Putin has called Moscow's military goals "demilitarisation and denazification of Ukraine", as well as the imposition of neutral status.
Russia last week appeared to scale back its campaign when senior general Sergei Rudskoi said the first phase of the war was over and the "main goal" was now on controlling Donbas in the east.
The head of Ukraine's Lugansk separatist region says it may hold a referendum on becoming part of Russia.
Western analysts say Ukraine's unexpectedly dogged resistance, coupled with logistical and tactical failures by the Russians, explain any reorientation by Moscow.
Many in Ukraine remain suspicious that Russia could use this week's talks as an opportunity to regroup and fix the problems bedevilling its military.
UK Foreign Secretary Liz Truss said Monday that any peace deal between Kiev and Moscow must not "sell Ukraine out" and should include provisions to automatically re-trigger sanctions if Russia acts aggressively.
The Kremlin is taking no chances with domestic opposition to its war. A crackdown on independent reporting ensnared another victim on Monday after new warnings from Russia's media regulator.
The Novaya Gazeta newspaper, whose chief editor Dmitry Muratov was last year awarded the Nobel Peace Prize, said it was suspending publication until the end of the invasion.
Many foreign companies are giving up on Russia altogether, after a raft of Western sanctions. European brewers Carlsberg and Heineken joined the exodus Monday.
Russian oligarch Roman Abramovich and Ukrainian negotiators were targets of a suspected poison attack, potentially by Moscow hardliners seeking to sabotage peace talks, the Wall Street Journal reported Monday, citing people familiar with the matter.
The billionaire businessman, recently slapped with sanctions by Western nations seeking to pressure Russian President Vladimir Putin over his invasion of Ukraine, has reportedly been shuttling between Kyiv, Moscow and other negotiation sites.
But resistance in besieged Mariupol is the main obstacle preventing Moscow from gaining unbroken control of land from the Donbas to the Crimea.
In the southern town of Mykolaiv, under heavy assault for weeks, the bombardments appeared to be easing.