Sergiy Gaiday

A Russian missile strike on a crowded mall in central Ukraine killed at least 18 people in what Group of Seven leaders branded "a war crime" at a meeting in Germany where they looked to step up sanctions on Moscow.

Ukrainian forces prepared on June 24 to retreat from the strategic city of Severodonetsk after weeks of fierce fighting, a setback that could pave the way for Russia to seize a larger swath of eastern Ukraine.

EU leaders will gather in Brussels on June 23 to discuss calls to formally grant war-torn Ukraine "candidate status" to join the bloc, as Russian forces slowly advance in the eastern Donbas region despite fierce resistance from Kyiv's military.

Ukrainian forces are facing "massive" and relentless artillery attacks in a battleground eastern city, Kiev warned, as Russian troops gained ground throughout the Donbas region.

Moscow's troops have been pummelling eastern Ukraine for weeks and are slowly advancing, despite fierce resistance from the outgunned Ukrainian military.

President Volodymyr Zelensky hailed Brussels' support for Ukraine's European Union bid a historic achievement, as his country's eastern Donas region faced intense Russian shelling.

Ukraine's president has made an impassioned plea to Western allies to speed arms deliveries and help stem "terrifying" casualties as Russian forces lay siege to the eastern city of Severodonetsk, destroying the last bridges into the industrial hub.

Ukrainian and Russian forces were fighting for "literally every metre" in Severodonetsk, President Volodymyr Zelensky said, as fighting intensified in an eastern region where the country's top commander said the land "is covered in blood".

Severodonetsk and nearby Lysychansk have been targeted for weeks as the last areas in the Lugansk region still under Ukrainian control.

President Volodymyr Zelensky said Ukrainian forces were "holding on" in the flashpoint eastern city Severodonetsk where intense street battles with Russian troops could determine the fate of the Donbas region.

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.

Ukraine marked 100 days since Russia's invasion on Friday with fighting raging across the east of the country, where Moscow's forces are tightening their grip on the Donbas region.

The sombre milestone came as Kiev announced Moscow was now in control of a fifth of Ukrainian territory, including Crimea and parts of Donbas seized in 2014.