A column of tanks advancing towards Kyiv has made "little discernible progress" since Tuesday and remains more than 18 miles from the centre of the capital, according to the British Ministry of Defence.
The delay is due to "staunch Ukrainian resistance, mechanical breakdowns and delays," the ministry said.
Kharkiv, Chernihiv and Mariupol remain under Ukrainian control despite continued heavy Russian shelling, it continued, while the situation in Kherson remains unclear after Russian forces entered the city. Russia had claimed it had seized control over the southern port city.
The ministry noted that Russia's own defense ministry has also for the first time announced casualties suffered since first attacking Ukraine last Thursday, reporting 498 dead and 1,597 wounded.