What you need to know right now:
- Rockets hit the Ukrainian city of Lviv for the apparent first time in Russia's month-long war.
- US President Joe Biden, visiting Nato ally Poland, called Russian President Vladimir Putin a "butcher" during a meeting with refugees and later said he "cannot remain in power".
- Russian forces have taken control of the town of Slavutych where workers at the defunct Chernobyl nuclear plant live, the governor of Kyiv region said.
- The mayor of the besieged southeastern port of Mariupol, Vadym Boichenko, said the situation in city remained critical, with street fighting taking place in its centre.
- The war in Ukraine has killed 136 children in the 31 days since the start of the Russian invasion, Ukraine's office of the prosecutor general said.
- Ukraine's new agriculture minister Mykola Solskyi said Ukraine's ability to export grains was getting worse by the day and would only improve if the war with Russia ends.
- Russia said on Friday the first phase of its military operation in Ukraine was mostly complete and it would focus on "liberating" the Donbass region.
Updated 10pm
Rockets struck the western Ukrainian city of Lviv on Saturday, signalling a potential new front in Moscow's invasion as US President Joe Biden decried Russian President Vladimir Putin's power and sought to steel Europe for a long fight ahead.
Intense fighting raged in several parts of Ukraine, suggesting there will be no swift let-up in the month-old war while Biden framed the fight as part of the historic struggle for democratic freedoms in a major address from Poland as he concluded his European trip aimed at bolstering Western resolve.
"For God's sake, this man cannot remain in power," Biden said in Warsaw. A White House official later said Biden was not calling for regime change but was saying "Putin cannot be allowed to exercise power over his neighbours or the region."
The Kremlin dismissed Biden's comment, saying it was "not for Biden to decide."
After more than four weeks of fighting, Russia has failed to seize any major Ukrainian city and the conflict has killed thousands of people, sent nearly 3.8 million abroad and driven more than half of Ukraine's children from their homes, according to the United Nations.
Moscow signalled on Friday it was scaling back its military ambitions to focus on territory claimed by Russian-backed separatists in the east.
But two rockets hit the outskirts of Lviv, some 60 kilometres from the Polish border, a city that so far had escaped the heavy bombardment and fighting that has devastated some Ukrainian cities closer to Russia.
Regional Governor Maksym Kozytskyy said five people had been wounded and residents were told to head to shelters after three powerful blasts in mid-afternoon. Reuters witnesses saw black smoke rising from the northeast side of the city and Lviv's mayor said an oil storage facility had been hit.
Russian troops seized Slavutych, a town where workers at the nearby Chernobyl plant live, the regional governor said.
He said Russian forces had fired into the air and thrown stun grenades to disperse residents who unfurled a large Ukrainian flag and shouted "Glory to Ukraine" in protest. Reuters could not independently verify the reports.
Slavutych sits just outside the so-called exclusion zone around Chernobyl, which was the site of the world's worst nuclear disaster in 1986.
Ukrainian staff have continued to work at Chernobyl after the plant was seized by Russian forces soon after the start of the February 24th invasion, and the International Atomic Energy Agency (IAEA) has expressed alarm about the situation if workers are unable to rotate.
In the encircled southern city of Mariupol, Mayor Vadym Boichenko said the situation remained critical, with street fighting in the centre. Mariupol has been devastated by weeks of Russian fire.
In an address to Qatar's Doha Forum, Ukrainian President Volodymyr Zelenskiy compared the devastation in Mariupol to the destruction inflicted on the Syrian city of Aleppo by combined Syrian and Russian forces in Syria's civil war.
"They are destroying our ports," Zelenskiy said, warning of dire consequence if his country - one of the world's major grains producers - could not export its foodstuffs. "The absence of exports from Ukraine will deal a blow to countries worldwide."
Speaking via video link, he also called on energy producing countries to increase their output so that Russia cannot use its oil and gas wealth to "blackmail" other nations.
'Butcher'
Meanwhile, Biden saw Ukrainian Foreign Minister Dmytro Kuleba and Defence Minister Oleksii Reznikov in the Polish capital Warsaw in his first face-to-face meeting with top Ukrainian officials since the start of the war.
Biden described Putin as a "butcher" after touring a food kitchen for Ukrainian refugees.
Biden's visit to Poland was his final stop on a trip to Europe that has underscored his opposition to the Russian invasion, his solidarity with Ukraine and his determination to work closely with Western allies to confront the crisis.
"We are waiting for President Biden to close the sky over Ukraine. Ukrainian warriors can protect our country on the ground, but we can't close the sky," said Alla Dyachenko, a chemist from Kyiv who fled to Poland with her daughter.
Nato has ruled out a no-fly zone over Ukraine, fearing it would lead to direct clashes with Russian forces and a Europe-wide escalation.
Zelenskiy pushed late on Friday for further talks with Russia after its defence ministry said a first phase of its operation in Ukraine was mostly complete and that it would now focus on the Donbass region bordering Russia, which has pro-Moscow separatist enclaves.
Russian-backed forces there have been fighting pro-government forces since 2014.
Reframing Russia's goals may make it easier for Putin to claim a face-saving victory, analysts said.
Moscow has until now said its goals for what it calls its "special military operation" include demilitarising and "denazifying" its neighbour. Ukraine and its Western allies have called that a baseless pretext for an unprovoked invasion.
The United Nations has confirmed 1,104 civilian deaths and 1,754 injuries in Ukraine since the invasion but says the real toll is likely higher. Ukraine says 136 children have been killed.
Russia's defence ministry said 1,351 Russian soldiers had been killed and 3,825 wounded, the Interfax news agency reported on Friday. Ukraine says 15,000 Russian soldiers have been killed. Reuters could not independently verify the claims.
A British intelligence report said Russian forces were relying on indiscriminate air and artillery bombardments rather than risk large-scale ground operations, a tactic the report said could limit Russian military casualties but would harm more civilians in Ukraine.
