Russia has accused Ukrainian President Volodymyr Zelensky of making "irresponsible" threats after he said Moscow's top officials should check for bomb shelters near the Kremlin if the country does not stop its offensive on Ukraine.
In an interview with US media outlet Axios, Mr Zelensky said Russian officials "have to know where their bomb shelters are," adding: "If they will not stop the war, they will need it in any case."
Russia earlier this month struck the Ukrainian government complex in Kyiv for the first time in the three-and-a-half-year conflict as it launched its biggest aerial barrage on Ukraine.
"Zelensky is clearly continuing his desperate efforts. That's why he's issuing threats left and right, which is quite irresponsible," Kremlin spokesman Dmitry Peskov told journalists at a briefing.
US and European backing for Ukraine's ability to strike deep inside Russia has often wavered, with Washington and European capitals nervous of provoking Moscow into an expanded conflict.
However, Ukraine is now frequently targeting Russian energy facilities, repeatedly striking notably its refineries, and Mr Zelensky said US President Donald Trump had given him the green light to continue.
The Kremlin has also said that it did not want to talk about a Bloomberg report that European diplomats had privately warned Moscow that NATO would be ready to shoot down any Russian aircraft violating European airspace.
Bloomberg reported, citing officials familiar with the exchange, that British, French and German envoys had delivered the warning at a meeting in Moscow.
Asked how Russia would respond if NATO shot down a Russian plane, Mr Peskov said: "You know, I don't even want to talk about this; it's a very irresponsible statement."
He added: "It's very irresponsible because accusations against Russia that its military aircraft violated someone's airspace and intruded into someone's skies are groundless. No convincing evidence has been presented."
NATO said Russian fighter jets violated Estonian airspace last week.
Ukraine's military chief says Russia's 2025 offensives have failed
Meanwhile, Ukraine's military chief Oleksandr Syrskyi said Russia's spring and summer offensives this year have failed to meet their goals, adding that Russia was firing twice as much artillery as Ukraine on the battlefield.
"It can be said that the Russians' spring and summer campaign has effectively been disrupted," Mr Syrskyi told reporters at a meeting.
Russia has been making incremental gains across several parts of the front line, after large-scale deployment of reconnaissance and attack drones has prevented quick progress of the sort seen in 2022.
Ukraine said the small advances are coming at a high human cost. Both sides in the war only rarely discuss casualties, but some Western intelligence estimates put the number of killed and wounded in Ukraine at more than one million.
Small Russian infantry assaults
Mr Syrskyi said the active front line was now 1,250km long, and that an estimated 712,000 Russian personnel were involved in the fighting in Ukraine.
Mr Syrskyi said Russian plans to create a "buffer zone" in Sumy and Kharkiv regions in the north and northeast, to take the city of Pokrovsk and to capture all of Donetsk region had failed.
The capture of all of Donetsk is a key aim of the war for Russia, which currently controls over 70% of the region.
Mr Syrskyi said that since the beginning of summer, the Russians had been attacking with a tactic that he called "a thousand cuts" - a high number of tiny infantry assaults.
"This consists of the simultaneous use of a large number of small assault groups - 4-6 servicemen who advance using the terrain, ravines, and wooded areas, with the main aim of penetrating as deeply as possible into our territory."
Speaking about a Russian breakthrough in August near the Donetsk town of Dobropillia, Mr Syrskyi said Ukraine had cut off Russian forces along the Kazenyi Torets river in what he called a "trap".
Sudden change in Trump's rhetoric
The commander added that in the last two months, Ukraine had hit 85 military or military-industrial facilities on Russian territory, including air bases, depots and factories.
This week, Mr Trump suddenly changed his view of the war from one where he said Kyiv had no cards to play to one where Ukraine could take back all of the ground it has lost so far - roughly 20% of its total territory.
He did not, however, offer substantial new assistance to Ukraine to achieve these goals and has shifted the onus onto European allies.
Russia said it is advancing in Ukraine and that Kyiv would be best advised to negotiate peace sooner rather than later.
Ukraine has rejected Russia's terms for negotiations, saying they would amount to surrender.
