“We can clearly say the offensive has started, as indicated by the Ukrainian army’s use of strategic reserves,” Putin told reporters in Sochi on Friday, where he was meeting with heads of other states in the Eurasian Economic Union.

“But the Ukrainian troops haven’t achieved their stated tasks in a single area of fighting,” he said. “We are seeing that the Ukrainian regime’s troops are suffering significant losses,” Putin said, without providing details.

“It’s known that the offensive side suffers losses of 3 to 1 – it’s sort of classic – but in this case, the losses significantly exceed that classic level,” he added.

With virtually no independent reporting from the front lines and Kyiv saying little on its military operations, it was impossible to assess Putin’s claims or whether Ukraine was penetrating Russian defences in its bid to drive out occupying forces.

Authorities in Ukraine have either denied or declined to confirm if their counteroffensive has started, despite military analysts and sources in Ukraine stating that the campaign has begun to incrementally unfold amid reports of increased fighting in several regions along the front lines with Russian forces in the east and southeast of the country.

The Institute for the Study of War (ISW), a Washington, DC-based think tank, said on Friday that a “variety of indicators” suggested Ukraine’s counteroffensive had begun and warned that the early phase of the campaign “may also see the highest Ukrainian losses” as efforts are made to push through the front lines against defending Russian forces.

According to the ISW, Putin directly addressing Ukraine’s counteroffensive was an important departure for the Russian president who has maintained a “distanced approach to discussing battlefield realities”.

The Kremlin reportedly adopted a new information policy aimed at playing up the “Russian fight against Western-provided weapon systems” in Ukraine’s counteroffensive, the ISW said on Saturday.

2/ Russian President Vladimir #Putin acknowledged on June 9 that the Ukrainian #counteroffensive recently began & noted that Ukrainian forces still have offensive potential, a departure from previous Kremlin efforts to downplay Ukrainian counteroffensives. https://t.co/ilySwoUjWw

— ISW (@TheStudyofWar) June 10, 2023

Russian claims that the counteroffensive had been blunted – a point played up by pro-Moscow military bloggers focusing on destroyed and damaged Western military equipment donated to Ukraine – were premature, the ISW said.

“Ukrainian officials directly acknowledged that Ukrainian forces expect to suffer equipment losses during counteroffensive operations,” the ISW said in its latest report. The ISW earlier said that the initial phase of Ukraine’s counteroffensive operations will likely be the most costly and difficult in terms of lives lost and equipment destroyed.

“Militaries have long identified the penetration phase of a mechanised offensive as the most dangerous and costly. The success or failure of this phase may not be apparent for some time,” the ISW said.

In his nightly address on Friday, Ukrainian President Volodymyr Zelenskky again praised the heroism of his forces, “for all those who are in particularly tough battles these days”.

“We see your heroism, and we are grateful to you for every minute of your life – a life that is truly the life of Ukraine,” he said.

Earlier on Friday, Ukrainian Deputy Defence Minister Hanna Maliar said Russia was on the defensive in the southeastern Zaporizhia region, though the epicentre of fighting remained in the east, particularly in the Donetsk region.

She described “heavy battles” in Lyman, Bakhmut, Avdiivka and Marinka.

Valerii Shershen, a spokesperson for Ukraine’s armed forces in Zaporizhia, told Radio Liberty that Ukrainian forces were searching for weaknesses in Russia’s defence, which Moscow was trying to strengthen by deploying mines, constructing fortifications and regrouping.

A Ukrainian military success in the Zaporizhia region would enable its forces to break through the land bridge that connects Russia with the Moscow-annexed Crimean peninsula.

That would be a significant reversal for Russia.

The main element of the Ukrainian counteroffensive, when it unfolds, is expected to involve thousands of Ukrainian troops trained and equipped by the West.

In all, Kyiv has 12 brigades totalling 50,000-60,000 troops ready to deploy in the counteroffensive. Nine of the brigades have been armed and trained by the West.

Ben Barry, senior fellow for land warfare at the International Institute for Strategic Studies, said Ukraine’s priority in the initial stages of the counteroffensive would be trying to keep the Russians off balance and gain tactical surprise through deception and camouflage.

The US Department of Defense also announced an additional $2.1bn in military assistance for Ukraine on Friday.

The latest package includes additional munitions for Patriot air defence systems, Raytheon HAWK air defence systems and missiles, 105mm and 203mm artillery rounds, small AeroVironment drones that can be launched by hand, laser-guided rocket system munitions and support for training and maintenance, the defence department said.