Ceding any territory in the eastern part of Ukraine to Russia is a deal breaker and not up for negotiation, Ukrainian President Volodymyr Zelensky said in an interview that aired Sunday.

As Russian forces gear up for an expected major offensive in the eastern part of Ukraine, the Ukrainian leader appeared on CNN’s State of the Union on Sunday and told host Jake Tapper that he will not consider giving up parts of his country in the Donbas region to bring an end to the war with Russia.