As Russia's invasion of Ukraine entered its third week, Kyiv accused Moscow of killing seven civilians, including one child, who were attempting to flee the fighting taking place near Kyiv.
The Ukrainian intelligence service said seven were killed as they fled the village of Peremoha and that "the occupiers forced the remnants of the column to turn back."
Reuters was unable immediately to verify the report and Russia offered no immediate comment. Moscow denies targeting civilians since invading Ukraine on Feb. 24 and blames Ukraine for failed attempts to evacuate civilians from encircled cities.
Ukrainian President Volodymyr Zelenskyy said earlier that Moscow was sending in new troops after Ukrainian forces put 31 of Russia's battalion tactical groups out of action in what he called Russia's largest army losses in decades. It was not possible to verify his statements.
He also said about 1,300 Ukrainian troops had been killed so far and urged the West to get more involved in peace negotiations. The president suggested Russian forces would face a fight to the death if they sought to enter the capital.
"If they decide to carpet bomb (Kyiv), and simply erase the history of this region ... and destroy all of us, then they will enter Kyiv. If that's their goal, let them come in, but they will have to live on this land by themselves," he said.
Zelenskyy discussed the war with Chancellor Olaf Scholz and President Emmanuel Macron, and the German and French leaders then spoke to Putin by phone and urged the Russian leader to order an immediate ceasefire.
A Kremlin statement on the 75-minute call made no mention of a cease-fire and a French presidency official said: "We did not detect a willingness on Putin's part to end the war."
Russian Deputy Foreign Minister Sergei Ryabkov accused the United States of escalating tensions and said the situation had been complicated by convoys of Western arms shipments to Ukraine that Russian forces considered "legitimate targets."
In comments reported by the Tass news agency, Ryabkov made no specific threat, but any attack on such convoys before they reached Ukraine would risk widening the war.
Responding to Zelenskyy's call for the West to be more involved in peace negotiations, a U.S. State Department spokesperson said: "If there are diplomatic steps that we can take that the Ukrainian government believes would be helpful, we're prepared to take them."
Crisis talks between Moscow and Kyiv have been continuing via a video link, Kremlin spokesperson Dmitry Peskov was quoted as saying by Russia's RIA news agency. He gave no details but Ukrainian Foreign Minister Dmytro Kuleba said Kyiv would not surrender or accept any ultimatums.
Air raid sirens blared across most Ukrainian cities on Saturday morning, local media reported.
Russian rocket attacks destroyed a Ukrainian airbase and hit an ammunition depot near the town of Vasylkiv in the Kyiv region, Interfax Ukraine quoted its mayor as saying.
The exhausted-looking governor of Chernihiv, around 150 kilometers (100 miles) northeast of Kyiv, gave a video update in front of the ruins of the city's Ukraine Hotel, which he said had been hit.
"There is no such hotel anymore," Viacheslav Chaus said, wiping tears from his eyes. "But Ukraine itself still exists, and it will prevail."
Britain's Defence Ministry said fighting northwest of the capital continued, with the bulk of Russian ground forces 25 kilometers from the center of Kyiv, which it has said Russia could attack within days.
Kharkiv, Chernihiv, Sumy and Mariupol remained encircled under heavy Russian shelling, it said.
Russia's invasion has been almost universally condemned around the world and that has drawn tough Western sanctions on Russia.
The Russian bombardment has trapped thousands of people in besieged cities and sent 2.5 million Ukrainians fleeing to neighboring countries. Zelenskyy said the conflict meant some small Ukrainian towns no longer existed.
An additional $200 million in Ukraine military aid approved by U.S. President Joe Biden on Saturday will provide assistance, including anti-armor weapons, anti-aircraft systems and small arms, a senior U.S. official said.
Russia calls its actions in Ukraine a "special operation" that it says is not designed to occupy territory but to destroy its neighbor's military capabilities and "de-Nazify" the country.
Ukrainian officials had planned to use humanitarian corridors from Mariupol as well as towns and villages in the regions of Kyiv, Sumy and some other areas on Saturday.
But Russian shelling threatened attempts to evacuate trapped civilians, they said.
A senior Russian defense ministry official said the humanitarian situation in Ukraine continued to decline rapidly and blamed Ukrainian fighters, accusing them of mining neighborhoods and destroying bridges and roads, the RIA news agency reported.
Russian officials have previously accused Ukrainian forces of shelling their own people and then seeking to blame Moscow, allegations that Kyiv and Western nations dismissed as lies.
The governor of the Kyiv region, Oleksiy Kuleba, said fighting and threats of Russian air attacks were continuing on Saturday morning though some evacuations were proceeding.
The Donetsk region's governor said constant shelling was complicating bringing aid into the southern city of Mariupol.
"There are reports of looting and violent confrontations among civilians over what little basic supplies remain in the city," the U.N.'s Office for the Coordination of Humanitarian Affairs said.
"Medicines for life-threatening illnesses are quickly running out, hospitals are only partially functioning, and the food and water are in short supply."
People were boiling groundwater for drinking, using wood to cook food and burying dead bodies near where they lay, a staff member for Medecins Sans Frontieres (Doctors without Borders) in Mariupol said.
"We saw people who died because of lack of medication," he said, adding that many people had also been wounded or killed. "Neighbours just dig a hole in the ground and put the dead bodies inside."
At least 1,582 civilians in Mariupol have been killed as a result of Russian shelling and a 12-day blockade, the city council said on Friday. It was not possible to verify casualty figures.
Efforts to isolate Russia economically have stepped up, with the United States imposing new sanctions on senior Kremlin officials and Russian oligarchs on Friday.
European Commission President Ursula von der Leyen said the EU would on Saturday suspend Moscow's privileged trade and economic treatment, crack down on its use of crypto-assets, and ban the import of iron and steel goods from Russia, as well as the export of luxury goods in the other direction.
