Russia’s defence minister, General Sergei Shoigu, has been urged to kill himself over defeats on the battlefield in a shocking broadside by one of the Kremlin’s own officials.

Kirill Stremousov, appointed head of Kherson region last week, spoke as Ukraine’s army announced that its counter-offensive had seized back almost 3000km2 of land from Russia.

In the southern prong of the assault in Kherson region, Kyiv’s forces have retaken 400 km2 and liberated nearly 30 towns and villages, according to a military spokeswoman. Moscow's army has also been evicted from 2,400km2 in the Kharkiv offensive in the north-east.

“A lot of people say that the defence minister, as an officer who let that happen, could shoot himself,” Mr Stremousov said in a video published on social media. “But you know what, the word ‘officer’ is not familiar for some people.”

In the four-minute clip, Mr Stremousov repeated that the city of Kherson was not in danger and its defence was “under lock and key”. Nevertheless, he suggested the majority of Russia’s military elite was made up of “useless and corrupt generals and looters”.

Mr Stremusov joined hands with Mr Putin on stage in Moscow last Friday as he was made the puppet leader of Kherson following sham referendums

While Russian bloggers have forcefully criticised the top brass, it is almost unheard of for someone within the fold of the Kremlin to publicly air such views.

Vladimir Solovyov, one of the most loyal propagandists on state television, earlier hit out at Russian generals for the slew of retreats, amid rising discontent with the progress of the invasion.

“Please explain to me what the general staff's genius idea is now?” he said on his live-stream channel. ”Do you think time is on our side? They (the Ukrainians) have hugely increased their amount of weapons... But what have you done in that time?“

Gen Shoigu, a key ally of Vladimir Putin, never served as a professional soldier and owes his rank to Russia’s tradition of granting commissions to defence ministers. He was widely praised within Moscow for the 2014 operation to annex Crimea, but analysts have begun to wonder if the Russian president might soon dispense with his services.

According to the Institute for the Study of War, a US-based think tank, Mr Putin has found it useful to keep Gen Shoigu on as a scapegoat for the rising level of criticism facing the invasion.

On Wednesday night, the heads of two parliamentary committees urged the prosecutor general to investigate an apparent supplies crisis in the Russian armed forces.

Andrei Gurulev, a State Duma deputy, said on state TV parliament will hold a closed hearing later this month to discuss “where all of those things went to.”

Putin 'would not survive' if he pressed the red button

Meanwhile, Volodymyr Zelensky, Ukraine’s president, on Thursday said he did not know if Kyiv’s success on the battlefield made it more likely that Russia would deploy a tactical nuclear weapon.

But he said Mr Putin would not survive if he pressed the red button.

“He understands that after the use of nuclear weapons he would be unable to preserve his life, so to say,” Mr Zelensky said.

Addressing European leaders at a summit in Prague on Thursday, he called for more support to ensure Russia does not extend his invasion to Warsaw or Prague.

Russia launched a missile attack on Thursday on a region it annexed only last week, theoretically placing it under Moscow’s protection.

At least three people were killed and 12 injured including a three-year old girl in the city of Zaporizhzhia in the early hours of Thursday, in the worst missile strike on the city since the start of the Russian invasion.

Over 20 people had been rescued from the rubble but more were still believed to be trapped.

Meanwhile, top Russian officials continue to signal the Kremlin’s willingness to stop the war as long as Kyiv agrees to cede some of its territory.

Speaking at a parliamentary assembly of G20 countries, Valentina Matviyenko, technically Russia’s third most senior official, urged her fellow lawmakers to sit down for talks to “try to understand each other and find a solution.”

The speaker of the upper chamber of the Russian parliament, however, rejected suggestions to give up back the swathes of Ukraine that Moscow has occupied and recently illegally annexed.

“This is out of the question: this is already part of Russia,” the Ukraine-born official said.

“We’re ready to stop the hostilities but on the conditions that Russia is offering.”