US President Joe Biden on Saturday castigated Vladimir Putin over the month-old war in Ukraine, bluntly calling the Russian leader "a butcher" who "cannot remain in power".
In an impassioned speech from the Royal Castle in Warsaw, delivered after meeting top Ukrainian ministers in Poland and earlier conferring with NATO and EU allies on the conflict, Biden plainly warned Russia: "Don't even think about moving on one single inch of NATO territory."
Although the White House moved quickly to temper Biden's unprecedented comments on Putin -- insisting the US leader is not seeking "regime change" in Russia and was referring to Putin's influence over neighbours in the region -- the Kremlin made its displeasure clear.
Personal attacks, one official said, were "narrowing down the window of opportunity" for bilateral relations.
Biden coupled his harsh words for Putin with a pointed attempt to appeal to ordinary Russians, saying they were "not our enemy" and urging them to blame their president for the heavy sanctions imposed by the West.
He offered reassurance to Ukrainians in the audience and elsewhere, at a time when nearly four million of them have been driven out of their country. "We stand with you," he said.
Biden also cast doubt on Russia's signal that it may scale down its war aims to concentrate on eastern Ukraine -- even as two Russian missile strikes slammed into the west of the country.
The president said he was "not sure" Moscow has indeed changed its objectives, which, so far, he said had resulted in "strategic failure".
Two Russian missiles earlier struck a fuel depot in western Ukraine's Lviv, a rare attack on a city just 70 kilometres (45 miles) from the Polish border, which has escaped serious fighting.
At least five people were wounded, regional governor Maksym Kozytsky said, as AFP journalists in the city centre saw plumes of thick black smoke.
Putin sent troops into Ukraine on February 24, vowing to destroy the country's military and topple pro-Western President Volodymyr Zelensky.
But his army has made little progress on capturing key cities, and it has hit hospitals, residential buildings and schools in increasingly deadly attacks on civilians.
- Unwavering -
Biden, who was winding up a whirlwind visit to Poland after holding a series of urgent summits in Brussels with Western allies, earlier met Ukraine's Foreign Minister Dmytro Kuleba and Defence Minister Oleksii Reznikov in Warsaw in an emphatic show of support for Kyiv.
Both ministers had made a rare trip out of Ukraine for the face-to-face talks, in a potential sign of growing confidence in their battle against Russian forces.
In a possible shift on a plan to transfer Soviet-era fighter jets from Poland to Kyiv to boost Ukraine's firepower in the skies -- rejected last month by the Pentagon as too "high risk" -- Kuleba said the United States now did not object.
"As far as we can conclude, the ball is now on the Polish side," Kuleba said in written comments to AFP after the meeting.
In a video address, Zelensky reiterated a call for planes while urging allies to supply Ukraine with more weapons.
"We need more ammunition. We need it to protect not only Ukraine but other Eastern European countries that Russia threatened to invade," he said.
"During the meeting... with our American colleagues in Poland we made it clear again," he said.
"What is NATO is doing? Is it being run by Russia? What are they waiting for? It's been 31 days. We are only asking for one percent of what NATO has, nothing more."
US Secretary of State Antony Blinken, meanwhile, announced an additional $100 million in aid to help Ukraine police and border guards purchase armoured vehicles, equipment and medical supplies, a statement said.
- 'Hiding losses' -
On the frontlines, Russia's far-bigger military continued to combat determined Ukrainian defenders who are using Western-supplied weapons -- from near the capital Kyiv to Kharkiv, the Donbas region and the devastated southern port city of Mariupol.
In an update Saturday night, the Ukrainian General Staff accused Russia of "hiding the real number of personnel and hardware losses".
In the eastern Kharkiv region, four soldiers and a civilian were killed Saturday when a Russian bombardment hit a high school in the town of Bervenkove, Ukrainian authorities said.
Russia's defence ministry reported a battle for control of two villages near the eastern separatist stronghold of Donetsk and also claimed a missile strike had destroyed an arms and ammunition depot in the Zhytomyr region, west of Kyiv, on March 25.
A humanitarian convoy leaving the devastated southern port of Mariupol -- including ambulances carrying wounded children -- arrived in Zaporizhzhia after being held up at Russian checkpoints for two days, a Ukrainian official said.
"The ambulances carrying wounded children are also queueing. The people have been deprived of water and food for two days," she wrote on Telegram, blasting Russian troops for "creating obstacles".
Authorities have said they fear some 300 civilians in Mariupol may have died in a Russian air strike on a theatre being used as a bomb shelter last week, with around 170,000 people still trapped in the besieged city.
It is very difficult to independently verify what is happening on the ground.
- 'Used to explosions' -
In Kharkiv, where local authorities reported 44 artillery strikes and 140 rocket assaults in a single day, residents were resigned to the incessant bombardments.
Anna Kolinichenko, who lives in a three-room flat with her sister and brother-in-law, said they don't even bother to head down to the cellar when the sirens go off.
"If a bomb drops, we're going to die anyway," she said. "We are getting a little used to explosions."
Artillery attacks in the city of Brovary, east of Kyiv, cost three lives, regional officials said in a statement, and a 19th century Orthodox church was destroyed.
Russian forces have taken control of Slavutych, the town where workers at the Chernobyl nuclear plant live, briefly detaining the mayor, regional Ukrainian authorities said.
Residents of the town protested, prompting the invading forces to fire shots in the air and lob stun grenades into the crowd.
Kyiv's mayor cancelled a planned 35-hour curfew, as Britain's defence ministry said Ukrainian counterattacks were underway near the capital.
"Enemy sabotage groups in Kyiv region are still attempting to penetrate the capital," the Ukrainian General Staff said.
Air-raid sirens sounded early Sunday in Kyiv and several other cities, with residents warned to take shelter.
Ukraine's defence ministry said its forces had recaptured Trostianets, a town near the Russian border that was one of the first to fall under Moscow's control.
Images published by the ministry showed Ukrainian soldiers and civilians among heavily damaged buildings and what appeared to be abandoned Russian military equipment.
In the face of unexpectedly fierce Ukrainian resistance, Russia's army has exhibited poor discipline and morale, suffering from faulty equipment and employing tactics sometimes involving brutality toward civilians, Western analysts say.
British Foreign Secretary Liz Truss said Saturday that UK sanctions against Russia could be lifted if Moscow committed to a full ceasefire and withdrew its troops.
Her comments echoed remarks by US Secretary of State Antony Blinken that the wide-ranging penalties against Russia are "not designed to be permanent" and could "go away" if Moscow changes its behaviour.
Latest developments
Here are the latest developments in the war in Ukraine:
- Biden meets Ukraine ministers -
President Joe Biden calls his Russian counterpart Vladimir Putin a "butcher" who "cannot remain in power" after meeting top Ukrainian ministers for the first time since Russia's invasion of Ukraine.
Within minutes of his comments in Warsaw, a White House official plays down the remarks, saying Biden "was not discussing Putin's power in Russia, or regime change".
Biden compares Ukraine's resistance against Russia to the anti-Soviet "battle for freedom", but warns that the world must prepare for a "long fight ahead".
- Over 3.7 million refugees -
More than 3.7 million people have fled Ukraine since Russia's invasion a month ago, the UN says.
The UN's refugee agency, UNHCR, says 3,772,599 Ukrainians have fled the country -- an increase of 46,793 from the previous day's figure.
Around 90 percent of them are women and children. The UN estimates that another 6.5 million people are displaced in Ukraine.
- Ukraine president calls for weapons -
In his latest video address, President Volodymyr Zelensky reiterates a call for planes while urging allies to supply Ukraine with more weapons.
"We need more ammunition. We need it to protect not only Ukraine but other Eastern European countries that Russia threatened to invade," he says.
"What is NATO is doing? Is it being run by Russia? What are they waiting for? It's been 31 days. We are only asking for one percent of what NATO has, nothing more."
- UK says sanctions could be eased with peace -
British Foreign Secretary Liz Truss says UK sanctions against Russia could be lifted if Moscow commits to a full ceasefire and withdraws its troops.
Truss says the Kremlin must also agree to "no further aggression" towards Ukraine for the British sanctions imposed on hundreds of people and entities to remain eased.
"Sanctions should only come off with a full ceasefire and withdrawal, but also commitments that there will be no further aggression," Truss tells the Sunday Telegraph.
- UK criticised over refugee policy -
Thousands of people rally in London in solidarity with Ukraine, as the capital's mayor steps up criticism of the government's response to the refugee crisis.
"We want the people of Ukraine to know that in their darkest hour, they are not alone," Sadiq Khan tells Sky News as the demonstrators gather.
The Labour mayor says he is "embarrassed" by the Conservative government's refugee policies. Red tape is hampering the generous response of the British people, he says.
- Missiles strikes on Lviv -
At least five people are wounded in two barrages of strikes that damage infrastructure including a fuel storage facility in a rare attack on the western Ukrainian city of Lviv.
Mayor Andriy Sadovy says the fuel storage facility caught fire after the first strikes, while the second round inflicted "considerable damage" to a defence facility in a residential area.
- Russia takes Chernobyl town -
Russian forces take control of a town where staff working at the Chernobyl nuclear site live and briefly detain the mayor, sparking protests, Ukrainian officials say.
"I have been released. Everything is fine, as far as it is possible under occupation," Yuri Fomichev, mayor of Slavutych, tells AFP by phone, but later reports the death of three civilians.
- Ukraine forces recapture town -
Ukraine says its forces have recaptured the northeast town of Trostianets, near the Russian border, one of the first towns taken in the Russian invasion.
Its defence ministry publishes images showing Ukrainian soldiers and civilians among heavily damaged buildings, and what appeared to be abandoned Russian military equipment along with a signpost to the town.
- Kyiv curfew cancelled -
The mayor of Ukraine's capital Kyiv cancels a curfew announced just hours earlier for the next day.
"New information from the military command: the Kyiv curfew will not enter into force tomorrow," mayor Vitali Klitschko announces on Telegram.
- Russian minister resurfaces -
Russia's defence minister Sergei Shoigu reappears on television after a two-week absence from view prompted questions from journalists.
No dates accompany the images on state television, but Shoigu refers to a finance ministry meeting that took place on Friday.
- Russia fuelling nuclear arms race: Zelensky -
Russia's "bragging" about its nuclear weapons is fuelling a dangerous arms race, Zelensky tells the Doha Forum.
"They are bragging that they can destroy with nuclear weapons not only a certain country but the entire planet," Zelensky says in a live video message to the forum.
Ukraine's leader calls on Qatar to increase production of natural gas to counter Russian threats to use energy as a weapon.
- Russia denies calling up reservists -
Russia denies it is planning to call up reservists, denouncing what it claims are "false" summons to Russian men by Kyiv's security services.
"The Russian defence ministry is not summoning and does not plan to summon any reservists to the military commissariats," spokesman Igor Konashenkov says in a statement.
- Turkey open to Russian oligarchs -
Russia's oligarchs can continue to do business in Turkey so long as they respect national and international law, Foreign Minister Mevlut Cavusoglu says.
Turkey has described Russia's invasion of Ukraine as "unacceptable" and has offered its services as a mediator to help end the war, but has not joined the sanctions imposed by the United States and EU member states.