Ukraine called on China on Saturday to join the West in condemning "Russian barbarism", as Moscow claimed it had struck a Ukrainian arms depot with hypersonic missiles in what would be the first use in combat of the next-generation weapons.
That attack, not far from the country's western Romanian border, came as Russia said its troops had broken through Ukrainian defences to enter the besieged southern port city of Mariupol, a scene of mounting desperation.
With the invasion in its fourth week, Kyiv's embattled leader Volodymyr Zelensky pressed for "meaningful" talks to halt fighting that has forced at least 3.3 million Ukrainians to flee their country.
The plea for China to condemn the invasion came from a top Zelensky advisor, Mikhailo Podolyak.
China could play an important role in global security, he said on Twitter, "if it makes a right decision to support the civilised countries' coalition and condemn Russian barbarism."
While Western countries have shown unity in the face of an invasion whose brutality has been clearly documented on social media, China has so far refused to condemn it.
Russia's claim Saturday to have unleashed its new hypersonic Kinzhal missile would mark a dramatic new escalation of its campaign to force Ukraine to abandon hopes of closer ties with the West.
Ukrainian air force spokesman Yuri Ignat told AFP that the arms depot in the western village of Deliatyn had indeed been hit but "we have no information of the type of missile".
Russian President Vladimir Putin, who unveiled the Kinzhal missile in 2018, has termed it "an ideal weapon" that flies at 10 times the speed of sound, making it extremely difficult for missile defenses to intercept.
In another setback, Ukraine officials admitted they had "temporarily" lost access to the Sea of Azov, though Russia has effectively controlled the coastline for weeks after surrounding Mariupol.
'Time to meet'
Zelensky on Saturday again appealed for peace, urging Russia to accept "meaningful" talks in his latest video posted on social media.
"This is the time to meet, to talk, time for renewing territorial integrity and fairness for Ukraine," he said.
"Otherwise, Russia's losses will be such that several generations will not recover."
But as in previous negotiations there appeared to be little progress in reaching a ceasefire.
Russia carried out air raids on Saturday on the southern city of Mykolaiv in quick succession, Vitaly Kim, head of the regional administration, said, a day after a deadly strike on a military barracks there.
Less than 100 kilometres to the southeast, Ukraine claimed that a Russian general had been killed by strikes on an airfield outside Kherson, just north of Crimea. Ukraine said he was the fifth top-ranking officer killed since the invasion began on February 24.
British Foreign Secretary Liz Truss said Saturday that Moscow was using talks as a "smokescreen" as it carried out "appalling atrocities".
Fierce resistance has managed to stall Russian forces outside Kyiv and several other cities in the east, making them vulnerable to Ukrainian attacks against supply lines.
Britain's defence ministry said that Russia has been forced to "change its operational approach and is now pursuing a strategy of attrition."
"This is likely to involve the indiscriminate use of firepower resulting in increased civilian casualties," it warned.
Friday's attack on the arms depot was the latest strike in western Ukraine, which until a few days ago had remained relatively unscathed by Russia's push toward key cities from the north and east.
Also on Friday, Russian forces destroyed an aircraft repair plant near the airport of Lviv, the city where millions of people have fled as rockets and shelling continue to rain down on Kyiv.
In Mariupol, rescuers were still searching Saturday for hundreds of people trapped under the wreckage of a bombed theatre where more than 1,000 people had been seeking shelter when it was struck on Wednesday.
There was still no information about potential fatalities, Zelensky said, but 130 people had been saved so far, some "heavily injured."
"This is no longer Mariupol, it's hell," said resident Tamara Kavunenko, 58. "The streets are full with the bodies of civilians."
After weeks cut off from food, water and electricity, the situation in Mariupol has become "extremely dire," the UN refugee agency said Friday.
Tweeting a photo of the wrecked theatre, Foreign Minister Dmytro Kuleba asked multinational companies that were "still working with or in Russia: how can you keep doing business with them?"
His question echoed comments by Zelensky during a live video address to a Swiss rally in which he blasted firms such as Nestle for not severing ties.
Appeals to China
Russia's ally China told US President Joe Biden on Friday that the war was "in no one's interest," but showed no sign of giving in to the pressure to join Western condemnation of Russia.
Biden warned his Chinese counterpart Xi Jinping of "consequences" for any financial or military aid for Russia, a move that could turn the standoff into a global confrontation.
Putin appears undeterred by further threats or sanctions, holding a triumphalist rally in Moscow on Friday to mark eight years since Russia's seizure of Crimea, saying his goal in Ukraine was "to rid these people from their suffering and genocide."
Russia wants Ukraine to disarm and disavow all Western alliances, in particular to renounce joining NATO or to seek closer integration with the European Union -- steps that Kyiv says would turn it into a vassal state of Moscow.
Russia's top negotiator said Friday that Moscow and Kyiv had brought their positions "as close as possible" on a proposal for Ukraine to become a neutral state.
But Podolyak, the Zelensky advisor, said his country's position had not budged.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)