British military intelligence said on Thursday that Russia had partially regained control over the approaches to the eastern Ukrainian town of Kreminna, after its troops were pushed back from the region earlier this year.
"In places, Russia has made gains of up to several kilometers," the military intelligence said in an update, adding that Russian commanders are likely trying to expand a security zone and are also seeking to recapture the logistic hub of Kupiansk in Kharkiv.
Russian forces earlier on Thursday unleashed a wave of air strikes in the north and south of Ukraine a day after Russian President Vladimir Putin bid farewell to Chinese leader Xi Jinping following a two-day visit to Moscow.