* Russian forces pour resources into battle
* City of Sievierodonetsk under assault
* Ukraine pleads for more weapons from West
* EU cannot agree on Russian oil embargo; more talks Monday
KYIV/KHARKIV, Ukraine, May 29 (Reuters) - Russian forces
intensified their attacks with barrages of heavy artillery to
capture a key Ukrainian city in the southeastern region of
Donbas, whose full takeover Moscow's top diplomat said was now
an "unconditional priority."
Constant Russian shelling has destroyed all of the critical
infrastructure in Sievierodonetsk, the largest city Ukraine
still controls in Luhansk, one of the regions in Donbas,
Ukrainian President Volodymyr Zelenskiy said, while pledging to
do everything to hold off the advance.
"Some 90% of buildings are damaged. More than two-thirds of
the city's housing stock has been completely destroyed. There is
no telecommunication," he said in a televised speech.
"Capturing Sievierodonetsk is a fundamental task for the
occupiers ... We do all we can to hold this advance," he added.
The "liberation" of the Donbas, an industrial region which
includes Luhansk and Donetsk, is an "unconditional priority" for
Russia, Foreign Minister Sergei Lavrov said on
Sunday.
In a Facebook post, Ukrainian forces in the Donbas said they
had been on the defensive all day on Sunday. Russian forces
fired on 46 communities in the Donetsk and Luhansk regions,
killing at least three civilians, wounding two others or
destroying or damaging 62 civilian buildings.
Russian shelling also continued across several regions such
as in Novy Buh in Mykolaiv and Sumy. The city council in Novy
Buh in Mykolaiv region in southern Ukraine said on its Telegram
channel that a Russian missile attack had caused considerable
damage in the city center.
The battle for Sievierodonetsk, which lies on the eastern
bank of the Siverskyi Donets River, is in the spotlight as
Russia ekes out slow but solid gains in the part of the country
close to the Russian border.
Having failed to take the capital Kyiv in the early phase of
the war, Russia is seeking to consolidate its grip on the
Donbas, large parts of which are already controlled by
Moscow-backed separatists.
It has concentrated huge firepower on a small area - a
contrast to earlier phases of the conflict when its forces were
often spread thinly - bludgeoning towns and cities with
artillery and air strikes.
The Ukrainian government meanwhile urged the West to provide
it with more longer-range weapons in order to turn the tide in
the war, now in its fourth month. Zelenskiy voiced hopes that
the weapons would be provided and that he expected "good news"
in the coming days.
U.S. officials have said such weapons systems are actively
being considered.
Analysts at the Institute for the Study of War in Washington
said the Russians had still not managed to encircle
Sievierodonetsk and the Ukrainian defenders have inflicted
"fearful casualties" on them.
The Ukrainians were taking serious losses themselves,
civilians as well as combatants, they said in a briefing paper.
Russia's focus on Sievierodonetsk had drawn resources from
other battlefronts and as result they had made little progress
elsewhere, the analysts said.
A Reuters journalist in the area said a ceramics factory was
almost completely destroyed on the outskirts of the Donetsk town
of Bakhmut, which straddles the last main road into
Sievierodonetsk and is just 10 km (6 miles) from the frontline.
The journalist heard what appeared to be outgoing artillery
fire and Russian aircraft dropping a bomb close to the town.
Several transporters with Ukrainian soldiers could be seen in
the area.
EMBARGO ON RUSSIAN OIL
Russia says its "special military operation" aims to rid
Ukraine of nationalists threatening Russian-speakers. Ukraine
and Western countries say Russia's claims are a false pretext
for a war of aggression and the West has imposed a barrage of
sanctions targeting Moscow while delivering shipments of weapons
to help the Ukrainian government defend itself.
However, after nearly half a dozen rounds of punitive
measures, some against oligarchs close to Russian President
Vladimir Putin and banks, the unity within the European Union is
being put to fresh test as the bloc on Sunday failed to agree on
an embargo of Russian oil. Talks will continue on Monday.
German Economy Minister Robert Habeck expressed fears that
EU unity was "starting to crumble." The bloc's leaders are set
to meet on Monday and Tuesday in a summit to discuss a new
sanctions package against Russia including the oil embargo.
Meanwhile Zelenskiy - who has won widespread admiration in
the West for his leadership in the conflict - visited Ukrainian
troops on the frontlines in northeastern Kharkiv region.
Several explosions were heard in Kharkiv city hours after
Sunday's visit, a Reuters journalist said, in what was
Zelenskiy's first trip outside the Kyiv region since the
invasion began.
A large plume of smoke could be seen rising northeast of the
center of the city, which has been the target of Russian
shelling in recent days after several weeks of relative quiet.
"You risk your lives for us all and for our country," the
president's office quoted him as telling soldiers as he handed
out commendations and gifts.
(Reporting by Natalia Zinets, Conor Humphries, Pavel Polityuk
and Bogdan Kochubey in Kyiv, David Ljunggren in Ottawa, Lidia
Kelley in Melbourne; Writing by Angus MacSwan and Humeyra Pamuk;
Editing by Grant McCool and Stephen Coates)