A first round of talks between the foreign ministers of Russia and Ukraine has failed to yield progress on a ceasefire, Ukraine says.
Speaking after the meeting in Turkey, Dmytro Kuleba said that the demands his Russian counterpart Sergei Lavrov had made amounted to a surrender.
Mr Lavrov meanwhile said his country’s military operation was going to plan.
The talks come after Russia bombed a children’s hospital, which Ukraine said was a “war crime”.
Officials say three people including a child died in the attack in the south-eastern city of Mariupol.
Russia launched a full-scale invasion of Ukraine two weeks ago and more than 2.3 million people have since fled the country.
The worst humanitarian situation was in Mariupol, Mr Kuleba said, where residents have been trapped for days in freezing temperatures without electricity or water.
But Russia had not committed to establishing a humanitarian corridor there and had also not responded to proposals for a 24-hour humanitarian ceasefire across Ukraine, he said.
“I want to repeat that Ukraine has not surrendered, does not surrender, and will not surrender,” he said, adding that he was willing to continue meeting.
For his part, the Russian foreign minister offered no concessions and repeated demands that Ukraine be disarmed and accept neutral status. Moscow was waiting for a reply from Kyiv, he said.
Mr Lavrov also accused the West of fuelling the conflict by supplying weapons to Ukraine.
Russia would cope with Western sanctions and “come out of the crisis with a better psychology and conscience”, he said.
“I assure you we will cope and will do everything not to rely on the West ever, in any areas of our lives,” he said.
Outcry at hospital bombing
UN Secretary General António Guterres described the attack as “horrific” and the US accused Russia of a “barbaric use of military force to go after innocent civilians”.
But at his press conference Mr Lavrov dismissed allegation of a war crime in Mariupol, alleging that the maternity hospital had been occupied by Ukrainian forces.
Mariupol – where about 400,000 people live – has been surrounded by Russian forces for several days, and repeated attempts at a ceasefire to allow civilians to leave have broken down.
“The whole city remains without electricity, water, food, whatever and people are dying because of dehydration,” Olena Stokoz of Ukraine’s Red Cross told the BBC on Wednesday.
Chemical weapons warning
Western officials – including the White House – have warned Russia could use chemical or biological weapons in Ukraine or create a “false flag” operation – a misleading operation blamed on the other side, usually used to justify a supposed counter-attack.
At his press conference Mr Lavrov repeated Russia’s claim that the Pentagon was using Ukrainian territory to develop pathogens that could be used to create biological weapons – an assertion the US has called “preposterous”.
He also alleged that Ukraine had been preparing an attack against two Russia-backed separatist regions in eastern Ukraine.
Moscow earlier said Ukrainian forces had transported some 80 tonnes of ammonia in the country’s north-east, without providing evidence.
The US House of Representatives voted in favour of nearly $14bn (£10.6bn) in aid for Ukraine, as well as voting to ban US imports of Russian oil and other energy products. The measures still must pass through the Senate, which is expected to vote later this week.
Meanwhile US Vice-President Kamala Harris is in Poland, a day after Washington rejected the country’s plan to transfer military jets to the US, rather than directly to Ukraine.
And in Europe, EU leaders are meeting in France’s Palace of Versailles for a two-day summit to discuss Ukraine’s possible future membership, more sanctions on Russia, and a new common defence policy.
US officials estimated that between 5,000 to 6,000 Russian troops have been killed in Ukraine since the war began on 24 February.
Ukraine says more than 12,000 Russian service personnel have died, while Russia last week acknowledged 498 fatalities – but none of the competing claims can be clearly verified.