Biden, Macron condemn Putin as Ukraine claims up to 13,000 soldiers killed in war

As many as 13,000 Ukrainian soldiers have been killed since Russia invaded Ukraine in February, a Kyiv official has said.

According to reports, Mykhailo Podolyak, an adviser to Ukrainian President Volodymyr Zelenskyy, said this was the "number of dead", adding that many more soldiers had been wounded.

It is rare for Ukraine to reveal causality figures and Podolyak's comments have not been confirmed by the Ukrainian military, sources reported.

Speaking to Ukrainian TV outlet Channel 24 he said: "We have official evaluations by the General Staff, official evaluations by the commander-in-chief , and they range from 10,000 to 12,500-13,000 killed," he said.

Ukraine has been keeping up military pressure on Russia, but things are getting difficult as freezing temperatures set in. Russia has been attacking Ukraine's energy infrastructure, with the NATO accusing Russia of using winter as a weapon.

NATO Secretary General Jens Stoltenberg said Putin was intent on using frost, snow and ice to his advantage, not just on the battleground but against Ukrainian civilians.

Kyiv's mayor on Thursday warned residents of a total blackout caused by Russian strikes and urged them to stock up on water, food and warm clothes. 

Vitali Klitschko said that in such a scenario, temperatures could drop massively in the Ukrainian capital, and residents might have to be evacuated. 

Power units at several power stations across Ukraine had to conduct emergency shutdowns this week after a spate of Russian missile strikes.

On Thursday, Ukraine claimed that Russia is now using dummy nuclear-capable missiles with non-explosive warheads to exhaust Ukraine's air defences.

Ukrainian military officials displayed what they said were fragments of Soviet-made X-55 cruise missiles - designed for nuclear use. These were found in Ukraine's two western regions.

Meanwhile, US President Joe Biden and his French counterpart Emmanuel Macron have agreed to stand together on Ukraine, with Biden hinting he could speak to Putin if the Russian leader was willing to end the war.

But Biden said he would only do this in consultation with his NATO allies and would do nothing that would harm Ukrainian interests.