BBC | A Russian missile attack on the Ukrainian city of Sumy, which killed 34 people - including two children - and injured 117 others, has been strongly condemned by Kyiv's Western allies.
Two ballistic missiles struck the city centre mid-morning on Sunday, exploding near the state university and congress centre, leaving bloodied bodies scattered in the streets.
US President Donald Trump described the attack as a "horrible thing" while Germany's chancellor-in-waiting, Friedrich Merz, accused Russia of committing a war crime.
There was no immediate official comment on the attack from Russia, whose forces across the nearby border are said to be preparing for a major offensive.
The attack comes as the US, Ukraine's strongest military ally, has been pursuing an end to the war - now in its fourth year - through negotiation under Trump.
Asked about the attack, the US president said it was "terrible" and that he had been "told they made a mistake", but did not elaborate.
Earlier, Trump's special envoy to Ukraine, retired Lt-Gen Keith Kellogg, said the attack had crossed "any line of decency".
Ukraine's leader Volodymyr Zelensky has urged Trump to visit Ukraine and see for himself the devastation brought by Russia's invasion.
"Please, before any kind of decisions, any kind of forms of negotiations, come to see people, civilians, warriors, hospitals, churches, children destroyed or dead," he said in an interview for CBS's 60 Minutes programme, recorded before the attack on Sumy.
Merz, who is expected to take over as Germany's new chancellor next month, told German public broadcaster ARD that the attack on Sumy constituted a "serious war crime".
"It was a perfidious act.. and it is a serious war crime, deliberate and intended," the conservative politician said.
Germany's outgoing Chancellor Olaf Scholz, meanwhile, said the attack showed "just what Russia's supposed readiness for peace [was] worth".
French President Emmanuel Macron accused Russia of "blatant disregard of human lives, international law, and the diplomatic efforts of President Trump".
"Strong measures are needed to impose a ceasefire on Russia," he said. "France is working tirelessly toward this goal, alongside its partners."
Describing the attack as "barbaric", European Commission President Ursula von der Leyen added: "Russia was and remains the aggressor, in blatant violation of international law.
"Strong measures are urgently needed to enforce a ceasefire. Europe will continue to reach out to partners and maintain strong pressure on Russia until the bloodshed ends and a just and lasting peace is achieved, on Ukraine's terms and conditions."
British Prime Minister Sir Keir Starmer also gave a view, saying he was "appalled at Russia's horrific attacks on civilians in Sumy".