Vladimir Putin was facing the prospect of further setbacks in Ukraine as he appeared to be preparing Russians for a possible scaling back of his ambitions away from seizing Kyiv to fighting for control of the east.

Ukrainian president Volodymyr Zelensky hailed his troops as having delivered “powerful blows” to the invading forces as he urged Moscow to negotiate an end to the month-long war.

An adviser to the Ukrainian ministry of defence, Markian Lubkivskyi, predicted troops could on Saturday take back Kherson, the first major city that the Kremlin’s forces seized.

He was sceptical that the Russian President’s aims had truly changed away from trying to take the whole nation, but said it does appear “the enemy is focused on the eastern part of Ukraine”.

Moscow gave its first indication it could scale back its offensive when it said the “special military operation” would now focus on the “main goal, liberation of Donbas”, which borders Russia in the east of Ukraine.

Mr Zelensky’s forces were already believed to be regaining ground around the capital of Kyiv and the UK Ministry of Defence (MoD) said Russians are “proving reluctant to engage in large scale urban infantry operations”.

Instead, the MoD said, they were preferring the “indiscriminate use of air and artillery bombardments in an attempt to demoralise defending forces”.

The Herald:

However, there were fresh signs it was Mr Putin’s troops who were struggling with morale, as Western intelligence suggested a Russian brigade commander, Colonel Medvechek, was deliberately run down and possibly killed by his own troops.

Mr Lubkivskyi told BBC Radio 4’s Today programme: “We cannot believe the statements from Moscow because there’s still a lot of untruth and lies from that side. 

“That’s why we understand the goal of Putin still is the whole of Ukraine.

“We can see now that the enemy is focused on the eastern part of Ukraine but we are ready for any kind of attacks in different Ukrainian places.”

The port city Kherson, in the south east, fell to the Russians early this month in their first major gain.

But Mr Lubkivskyi said: “I believe that today the city will be fully under the control of Ukrainian armed forces.

“We have finished in the last two days the operation in the Kyiv region so other armed forces are now focused on the southern part trying to get free Kherson and some other Ukrainian cities.”

Mr Zelensky claimed in his night-time address that more than 16,000 Russian troops had been killed in the conflict as he called for Moscow to negotiate, but warned he would not give up sovereign territory.

In the UK, Policing minister Kit Malthouse was sceptical about Moscow’s statements hinting at a scaling back of its operations.

“I’m not qualified to say, but what I do know is there’s an awful lot of misinformation and disinformation flying around in this awful conflict,” he said.

“And we need to take care that what first appears may not in fact be the truth. 

“Let’s hope there may well be a cessation of hostilities as soon as possible.”

Transport Secretary Grant Shapps signed new powers to seize two private jets worth tens of millions of pounds, one at Farnborough, the other at Biggin Hill, belonging to sanctioned Russian billionaire Eugene Shvidler.

“Putin’s friends who made millions out of his regime will not enjoy luxuries whilst innocent people die,” Mr Shapps said.

Facing unexpectedly fierce resistance, the Russian defence ministry said that having accomplished the “first phase” of military operations, its forces would concentrate on the Donbas region part-held by Moscow-backed separatist rebels.

Western officials said the Russian statement was a recognition its forces were overstretched and may have to “pause” operations around Kyiv and other cities while they focus on the east of the country.

Questions continued over how Nato would respond if Mr Putin uses chemical or biological weapons in Ukraine, as is it is feared he might in response to his military woes.

Boris Johnson said after meeting with leaders of the alliance in Brussels this week that he will keep a “bit of ambiguity” about the response but said it would be “catastrophic”.

President Joe Biden said it would be met with a “response in kind” depending on the “nature of the use”, though the White House clarified the US would not be using chemical weapons.

Conservative former security minister Baroness Neville-Jones suggested Nato could take some form of military, though would not say whether she thinks that would be strikes on Russia, on Moscow’s troops in Ukraine, or cyber attacks.

The former chair of the Joint Intelligence Committee told BBC Radio 4’s Any Questions?: “I don’t think it’s possible then to go on then with economic sanctions, it does have to be some kind of military response, there are a variety of responses you could take and it doesn’t have to be necessarily in Ukraine – you’ve got a very large land mass called Russia.

“Ministers are not going to indicate what they will do but I don’t think one should assume that it would just be in Ukraine.”

A western official said this week that the use of such weapons would mark a “fundamental change” in the Ukrainian conflict but said it was “highly unlikely” it would be met with Nato troops in Ukraine.

Nato estimates that in four weeks of fighting, between 7,000 and 15,000 Russia troops have been killed in combat, compared to the 15,000 they lost in 10 years in Afghanistan.