Ukraine expects to receive more weapons from allies after a fresh US pledge, President Volodymyr Zelensky says, as the battle for Ukraine’s east raged 100 days into Russia’s invasion.

Moscow’s forces occupy about 20 per cent of Ukraine’s territory, according to Mr Zelensky. Russian President Vladimir Putin’s forces are focusing on the industrial Donbas region, comprised of Luhansk and Donetsk, in the hope of a high-profile victory.

Three civilians were killed in Donetsk, including two in the coal-producing town of Avdiivka, and nine people were injured, Governor Pavlo Kyrylenko said late on Thursday. Reuters could not immediately confirm the details.

“The entire temporarily-occupied territory of our state is now a complete disaster zone, for which Russia bears full responsibility,” Mr Zelensky said in a late-night address.

“We are expecting more good news on weapon supplies from other partners … We are working to bring the supply of modern combat systems to a much higher level.”

Russia has accused Washington of adding “fuel to the fire” with a new $US700 million ($963 million) weapons package for Ukraine that will include advanced rocket systems with a range of up to 80 kilometres.

President Joe Biden’s administration has repeatedly said it had Ukraine’s assurances it would not use the rocket systems to hit targets inside Russia.

Russia says it is engaged in a “special military operation” to disarm and “denazify” its neighbour. Ukraine and allies call this a baseless pretext for a war that has killed thousands, flattened cities, and forced more than six million people to flee abroad.

While Moscow denies targeting civilians, it says it regards Ukrainian infrastructure used to bring in Western arms as a legitimate target.

But it has insisted Western supplies will not alter the course of its attack.

“Pumping (Western) weapons into Ukraine does not change all the parameters of the special operation,” Kremlin spokesman Dmitry Peskov told reporters.

“Its goals will be achieved, but this will bring more suffering to Ukraine,” Mr Peskov said when asked whether US plans to sell Ukraine drones that can be armed with missiles could change the nature of the conflict.

On the ground, the eastern industrial city of Sievierodonetsk is largely in ruins after days of fierce fighting.

Its capture and that of Lysychansk would give Russia control of all Luhansk, which like Donetsk is claimed by Moscow on behalf of separatists.

Seizing Luhansk would accomplish one of Mr Putin’s stated aims and shift battlefield momentum further in Russia’s favour after its forces were pushed back from the capital Kyiv and the north.

Moscow’s forces were also attempting to advance south towards the Ukraine-held cities of Kramatorsk and Sloviansk in Donetsk, governor Kyrylenko said.

The war and Western sanctions in response to it are taking a toll on the world economy, which is still dealing with the fallout from the coronavirus pandemic.

With its control of some of Ukraine’s biggest ports and critical Black Sea shipping routes, Russia has been blocking Ukrainian farm exports and deepening a global food crisis.

UN aid chief Martin Griffiths is in Moscow to discuss with Russian officials how the way can be cleared for exports of grain and other food from Ukraine’s Black Sea ports.

Russia and Ukraine account for nearly a third of global wheat supplies, while Russia is a key fertiliser exporter and Ukraine a major supplier of corn and sunflower oil.

Interfax news agency quoted Russia’s defence ministry as saying that vessels carrying grain could leave Ukraine’s Black Sea ports via “humanitarian corridors”, with Moscow ready to guarantee their safety.

As Washington blacklisted more individuals and entities with ties to the Kremlin, including a major steel producer and a cellist it called Putin’s middleman, the European Union gave final approval to sanctions that include a 90 per cent cut in Russian oil imports by the end of the year.

Moscow called the move “self-destructive”, saying it could destabilise global energy markets.

– AAP