Ukraine denies battle for Soledar is lost

Ukraine says its troops are still holding out despite heavy fighting on a battlefield covered with bodies in a salt mining town in the country's east, where Russian mercenaries have claimed Moscow's first significant gain in half a year.

The ultra-nationalist Russian mercenary group Wagner, run by an ally of President Vladimir Putin outside the normal chain of military command, has claimed to have taken Soledar after days of intense fighting that left it strewn with Ukrainian dead.

Moscow has so far held off proclaiming victory there.

Ukraine has acknowledged Russian advances but said on Thursday its own garrison had not withdrawn.

"Fighting is fierce," Ukrainian Deputy Defence Minister Hanna Malyar said in a briefing on Thursday, adding that the Russians were "moving over their own corpses".

Reuters was unable to independently verify the situation inside Soledar.

Malyar said Russia had increased the number of units in Ukraine to 280 from 250 in the past week as it seeks to gain the strategic initiative.

Kremlin watchers were trying to digest Russia's latest shift in battlefield leadership, a day after Valery Gerasimov, the chief of the military's general staff, was unexpectedly given direct command of the invasion.

The previous commander, Sergei Surovikin, was effectively demoted to become one of Gerasimov's three deputies.

Moscow explained the decision - at least the third abrupt change of command in the 11-month conflict - as a response to the growing importance of the campaign.

Russian and Western commentators alike saw attempts to shift blame for months of setbacks that have seen Russia lose about 40 per cent of the territory it had seized since February.

Chief of staff for more than a decade, Gerasimov had become a target of abuse from nationalist bloggers, many with hundreds of thousands of subscribers, who have flourished even as the Kremlin has shut all independent media and jailed its critics.

"The move is likely to be greeted with extreme displeasure by much of the Russian ultra-nationalist and military blogger community, who have increasingly blamed Gerasimov for the poor execution of the war," Britain's Ministry of Defence said.

One prominent Russian military blogger who posts on the Telegram messaging app under the name of Rybar said Surovikin was being made the fall guy for recent military debacles.

Other analysts wondered if it was Gerasimov who was being set up.

"Has Putin and Defence Minister (Sergei) Shoigu finally put in place all the elements to set up Gerasimov as the fall guy for all of Russia's failures in the war?" retired Australian major general Mick Ryan tweeted.

If Russia succeeds in capturing Soledar, it would be Moscow's biggest gain since a series of humiliating retreats in the second half of 2022.

But military experts say the cost has been disproportionate, after intense battles that littered the freezing mud with bodies.

Soledar had barely 10,000 people before the war and Russia has failed in repeated attempts to capture the far more important nearby city of Bakhmut, 10 times as large.

Ukrainian President Volodymyr Zelenskiy mocked the notion Russia's gains represented an important victory.

"Now the terrorist state and its propagandists are trying to pretend that some part of our city of Soledar - a city that was almost completely destroyed by the occupiers - is allegedly some kind of Russia's achievement," he said in an overnight address.

On Wednesday, Wagner boss Yevgeny Prigozhin said his forces had captured all of Soledar and killed about 500 Ukrainian troops after heavy fighting but the Kremlin was more cautious.

Donetsk governor Pavlo Kyrylenko told Ukrainian state TV 559 civilians remained in Soledar, including 15 children, and could not be evacuated as fighting continued.

Across Ukraine, the front lines have barely budged since Russia's last big retreat in the south two months ago.

Kyiv, which says it aims to drive out all Russian troops this year, is hoping the arrival of heavy armour from Western allies will allow it to resume advances in coming months.