LONDON -Britain will never accept the regions of Donetsk, Luhansk, Kherson and Zaporizhzhia as "anything other than Ukrainian territory" Prime Minister Liz Truss said, adding that Russian President Vladimir Putin was violating international law.
"Putin cannot be allowed to alter international borders using brute force. We will ensure he loses this illegal war," Truss said in a statement on Friday.
"Putin has, once again, acted in violation of international law with clear disregard for the lives of the Ukrainian people he claims to represent."
Later on Friday, Putin is due to proclaim Russia's rule over around 15% of Ukraine, the biggest annexation in Europe since Hitler.
Russia has held what it called referendums in occupied areas of Ukraine. Western governments and Kyiv said the votes breached international law and were coercive and non-representative.
Truss also spoke to Ukrainian President Volodymyr Zelenskiy earlier this week to say Britain would never recognise Russian attempts to annex its territory.
"The UK will never ignore the sovereign will of those people and we will never accept the regions of Donetsk, Luhansk, Kherson and Zaporizhzhia as anything other than Ukrainian territory," Truss said in her statement on Friday.