President Volodymyr Zelenskyy has told NATO leaders that Ukraine needs modern weapons and more financial aid in its fight against Russia's invasion.
"We need to break the Russian artillery advantage... We need much more modern systems, modern artillery," Mr Zelenskyy told a NATO summit in Madrid via video link on Wednesday.
He added that financial support was "no less important than aid with weapons".
"Russia still receives billions every day and spends them on war. We have a multibillion-dollar deficit, we don't have oil and gas to cover it," Mr Zelenskyy said, adding that Ukraine needs around $5 billion (A$7.2 billion) a month for its defence.
He also called for sanctions on Russia "that will stop its ability to pay for the war".
It comes as Russian forces struck at targets in the Mykolaiv area of southern Ukraine on Wednesday and intensified attacks on fronts across the country as NATO members met in Madrid to plan a course of action against the challenge from Moscow.
The mayor of Mykolaiv city said a Russian missile strike killed at least three people in a residential building there, while Moscow said its forces had hit what it called a training base for foreign mercenaries in the region.
In the east, the governor of said there was "fighting everywhere" in the battle around , which Russian troops were trying to encircle.
The governor of Kryvyi Rih in central Ukraine said Russian shelling had increased there too in the past few days.
"Several villages have been wiped from the face of the earth," Kryvyi Rih governor Oleksander Vilkul said.
The stepped-up attacks took place as Russian President Vladimir Putin's forces make slow but inexorable progress in a conflict now in its fifth month, and followed a missile strike on a shopping centre that killed at least 18 people in central Ukraine on Monday.
Nonetheless, Western analysts say the Russians are taking heavy casualties and running through resources, while the prospect of more Western weapons supplies reaching Ukraine, including long-range missile systems, made Moscow's need to consolidate any gains more urgent.
Far from the fighting, leaders of to thrash out policy in response to Russian actions, and also to any .
German Chancellor Olaf Scholz said members of the military alliance would supply Ukraine with weapons for as long as necessary.
United States President Joe Biden told the summit the United States was strengthening its forces in Europe based on threats from Russia.
NATO was also due to invite Sweden and Finland to become members, having overcome objections from Turkey.
Russia has long complained about a perceived expansion of Western blocs towards its borders, but its invasion of Ukraine - which it calls a "special military operation" - has served to give new impetus to NATO. The European Union has also awarded Ukraine candidate status in light of the invasion.
Civilian casualties
The mayor of Mykolaiv, Oleksandr Senkevych, said eight Russian missiles had struck the city, including hitting an apartment block. Photographs showed smoke billowing from a four-storey building with its upper floor partly destroyed.
Russia's defence ministry said its forces carried out strikes on a military training base for "foreign mercenaries" near the city and also hit eight ammo depots and a fuel dump.
News agency Reuters was not able to independently verify the reports.
A river port and ship-building centre just off the Black Sea, Mykolaiv has been a bastion against Russian efforts to push West towards Ukraine's main port city of Odesa.
The Mykolaiv strikes took place just two days after a . Rescuers were still searching for dozens of missing on Wednesday.
A Russian missile strike on a shopping centre in Ukraine on Monday killed at least 18 people. Source: Getty, Anadolu / Anadolu Agency/Anadolu Agency via Getty Images
Ukrainian President Volodymr Zelenskyy's office said the Russians had also fired missiles at civilian infrastructure in Sumy region in the past 24 hours, killing two civilians.
Britain's Ministry of Defence, in its regular assessment on the conflict, said it expected Russia to continue making strikes in an effort to hamper the resupplying of Ukrainian forces on the frontlines.
"Russia's shortage of more modern precision strike weapons and the professional shortcomings of their targeting planners will highly likely result in further civilian casualties," it said.
Ukrainian armed forces commander General Valery Zaluzhny said Russia had fired around 130 missiles on Ukraine within the last four days - an indication of the intensification of attacks.
Russia has denied targeting civilian areas but the United Nations says at least 4,700 civilians have been killed since Russia invaded Ukraine on 24 February.
Mr Zelenskyy addressed the United Nations Security Council remotely on Tuesday, describing Russia as a "terrorist state" and urging the Security Council, where Moscow has a veto, to expel it from the United Nations.
Eastern front
Fighting meanwhile raged further east in Luhansk province, a key battleground in Russia's assault on the industrial heartland of the Donbas region.
"There is fighting everywhere. The enemy is trying to break through our defences. And since they don't succeed, they fire with all the weapons they have, erase all the villages from the face of the earth," Luhansk governor Serhiy Gaidai said on television.
Rescuers removing rubble after a Russian missile attack on a school, Kharkiv, northeastern Ukraine, on 28 June, 2022. Source: AAP, Press Association / Madiyevskyy Vyacheslav/Ukrinform
Its capture would expand Russian control of the Donbas, one of Moscow's strategic objectives since its failure to seize Ukraine's capital Kyiv in the early stages of the war.
Referendum
The Moscow-imposed military-civilian administration in Kherson region said it had begun preparations for a referendum on joining Russia, Russian state news agency TASS reported.
Kherson, a port city on the Black Sea, sits just northwest of the Russian-annexed Crimean peninsula.
Russia-installed officials said their security forces had detained Kherson city mayor Ihor Kolykhayev on Tuesday after he refused to follow Moscow's orders. A local official said the mayor was abducted.
