US President Joe Biden on Saturday castigated Vladimir Putin over the month-old war in Ukraineand said that he “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 his 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, 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.

– 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 possible sign of growing confidence in their battle against Russian forces.

Speaking after visiting Ukrainian refugees later Saturday, Biden said he had been asked by children to pray for their relatives fighting in Ukraine.

“I remember what it’s like when you have someone in a war zone and every morning you get up and you wonder… You are praying you don’t get that phone call,” said Biden, whose son Beau served in Iraq before dying of a brain tumour.

US Secretary of State Antony Blinken, meanwhile, announced an additional $100 million in aid to help Ukraine police and border guards purchase armored vehicles, equipment and medical supplies, a statement said.

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.

A humanitarian convoy leaving Mariupol, including ambulances carrying wounded children, was being held up at Russian checkpoints, 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.

In Kharkiv, where local authorities reported 44 artillery strikes and 140 rocket assaults in a single day, residents were resigned to the incessant bombardments.

– ‘Used to explosions’ –

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, easy 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 said it was shortening a planned 35-hour curfew to just Saturday 8:00 pm to Sunday 7:00 am, as Britain’s defence ministry said Ukrainian counter-attacks were underway near the capital.

Ukrainian forces were also attempting to recapture Kherson, the only major city held by Russian invasion troops, a Pentagon official said.

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.