Russian artillery slammed Ukraine's eastern Donbas region with fierce fighting over the city of Severodonetsk, but the local governor said there was some progress in pushing back invading forces.
More than 100 days since President Vladimir Putin ordered Russian troops into Ukraine, thousands of people have been killed, millions sent fleeing and towns turned into rubble.
The advance of Russian forces has been slowed by stiff Ukrainian resistance, repelling them from around the capital Kyiv and forcing Moscow to focus on capturing the east, including the Donbas.
Some of the fiercest fighting has been centred on Severodonetsk, where Ukrainian troops are resisting a complete takeover.
"They (Russians) didn't seize it fully," Lugansk regional governor Sergiy Gaiday said Friday, saying the invading forces had been pushed back "20 percent".
"As soon as we get a big amount of Western long-range weapons, we will push their artillery back... and then Russian infantry will run."
Ukrainian troops were still holding an industrial zone in Severodonetsk, Gaiday had said, a scenario reminiscent of Mariupol, where a steelworks was the port city's last holdout.
The situation in Lysychansk -- Severodonetsk's twin city, which sits just across a river -- looked increasingly dire.
About 60 percent of infrastructure and housing had been destroyed, while internet, mobile networks and gas services had been knocked out, said its mayor Oleksandr Zaika.
In the city of Sloviansk, about 80 kilometres (50 miles) from Severodonetsk, the mayor has urged residents to evacuate in the face of intense bombardment, with water and electricity cut off.
"The situation is getting worse," student Gulnara Evgaripova told AFP as she boarded a minibus to leave the city.
Ekaterina Perednenko, a paramedic, said: "I am scared that there will be nothing to come back to."
- 'Shame and hatred' -
Russian troops now occupy a fifth of Ukraine's territory and Moscow has imposed a blockade on its Black Sea ports.
But Ukrainian President Volodymyr Zelensky was defiant on Friday.
"Victory will be ours," he said in a video speech.
Later, in his nightly address, he dismissed the Russian army.
"At first it looked threatening. Then dangerous... And now probably just a bitter smile," he said.
"Because what's left of it? ... War crimes, shame and hatred."
But Kremlin spokesman Dmitry Peskov said "certain results have been achieved", pointing to the "liberation" of some areas from what he called the "pro-Nazi armed forces of Ukraine".
The West has sent ever-more potent weapons to Ukraine and piled on ever more stringent sanctions against Moscow, with the European Union on Friday formally adopting a ban on most Russian oil imports.
Putin's alleged girlfriend, former gymnast Alina Kabaeva, was also added to an assets freeze and visa-ban blacklist.
- Food crisis -
The war has sparked fears of a global food crisis -- Ukraine and Russia are among the top wheat exporters in the world.
The United Nations said it was leading intense negotiations with Russia to allow Ukraine's grain harvest to leave the country.
Putin in a televised interview Friday said there was "no problem" to export grain from Ukraine, via Kyiv- or Moscow-controlled ports or even through central Europe.
The UN has warned that African countries, which imported more than half of their wheat consumption from Ukraine and Russia, face an "unprecedented" crisis.
Food prices in Africa have already exceeded those in the aftermath of the 2011 Arab Spring uprisings and the 2008 food riots.
On Friday, Putin met the head of the African Union, Senegalese President Macky Sall, at his Black Sea residence in Sochi.
After the meeting, Sall said he was "very reassured", adding that Putin was "committed and aware that the crisis and sanctions create serious problems for weak economies".
French President Emmanuel Macron, meanwhile, said Putin had made a "historic" error in starting the war.
But he said the Russian leader should not be "humiliated", and to leave room for diplomacy.
- Media driver killed -
A driver transporting two Reuters journalists in eastern Ukraine was killed and the two reporters were lightly wounded, a spokesman for the international news agency said.
A French volunteer fighter in Ukraine was also killed in combat, the French foreign ministry said Friday.
In areas around the capital Kyiv, which Russian troops retreated from at the end of March, some residents remain in desperate need of assistance.
At an aid distribution point in Horenka, northwest of Kyiv, a tearful Hanna Viniychuk, 67, said she had come for some basic necessities after losing her home to Russian bombardment.
"I'm grateful for this help," she said.