With Russian President Vladimir Putin's war in Ukraine entering its third week, officials in Mariupol said Russian warplanes again bombed the southern port city where a maternity hospital was pulverised on Wednesday.
The invasion has so far failed to reach its stated objectives. It has caused thousands of deaths and forced more than two million people to flee Ukraine, where several cities are under siege.
It has also hit a global economy that is still emerging from the effects of the coronavirus pandemic.
International Monetary Fund managing director Kristalina Georgieva said the war and the massive sanctions leveraged against Russia as punishment had triggered a contraction in global trade and sent food and energy prices sharply higher, which would lower the IMF's growth forecast next month.
She said she expected mounting pressure on Russia to end the war, given the spillover effects it was having on economies around the world.
Putin, facing global condemnation and increasingly isolated, said Russia would emerge stronger after overcoming the difficulties caused by the sanctions.
He told a government meeting there had been no alternative to what Russia calls its special military operation in Ukraine.
"There are some questions, problems and difficulties but in the past we have overcome them and we will overcome them," he said.
Russian Foreign Minister Sergei Lavrov and Ukraine's Dmytro Kuleba met in Turkey in the highest-level talks since Putin ordered the invasion on February 24.
Kuleba said Lavrov had refused to promise to hold fire to allow for aid distribution and the evacuation along humanitarian corridors of civilians trapped in Mariupol and elsewhere.
Lavrov showed no sign of making any concessions, saying the operation was going to plan and repeating Moscow's accusations that Ukraine posed a threat to Russia, which wants Kyiv to drop any aspirations of joining the NATO alliance.
A ceasefire was not meant to be on the agenda at Thursday's talks in Antalya, Lavrov said.
In Washington, Central Intelligence Agency director William Burns said Putin did not appear to have a "sustainable" end-game in Ukraine and might soon try to find a way to end the fighting.
Others, however, warned Putin could still seek to escalate.
"We have moved the dial for the process from zero to at least having the possibility for a discussion. But the indications of troop movements toward Kyiv may indicate that the worst may still be ahead of us," said Jonathan Eyal at the Royal United Services Institute in London.
Aid agencies say humanitarian help is most urgently needed in Mariupol, where residents are running out of food, water and power. Its capture would allow Russia to link pro-Moscow enclaves in the east and Russian-annexed Crimea to the south.
Attempts to send aid and evacuation convoys have failed for six days.
Russian warplanes targeted convoy routes on Thursday, said Petro Andrushenko, an adviser to Mariupol's mayor.
"They want to absolutely delete our city, delete our people. They want to stop any evacuation," he told Reuters by phone.
Lavrov said the hospital struck on Wednesday had stopped treating patients and had been occupied by Ukrainian "radicals".
Russia's defence ministry later denied having bombed the hospital, accusing Ukraine of a "staged provocation" there.
White House spokeswoman Jen Psaki called the hospital attack "horrific" and "barbaric", and said Washington was reviewing Russia's actions for possible war crimes.
European Commission President Ursula von der Leyen also said the "inhumane, cruel and tragic" attack could constitute a war crime and should be investigated.
Lavrov accused Western countries of inflaming the situation by arming Ukraine.
Russia says its offensive is aimed at disarming its neighbour and dislodging leaders it calls neo-Nazis. Kyiv and its Western allies say this is a baseless pretext to invade a democratic country of 44 million people.
The pounding of Mariupol underscored US warnings that the biggest assault on a European state since 1945 could become increasingly attritional.