From: Kyiv Independent — Moscow has long claimed that Donbass “belongs” to Russia because many they speak Russian — a false narrative echoed even by US special envoy to the Middle East Steve Witkoff, who suggested the region should be surrendered for that reason.
In reality, Donbas’s Russian-speaking identity is the result of centuries of Russification under the Russian Empire and the Soviet Union. Even so, most people in Donbas continued to identify as Ukrainian and wanted to be part of Ukraine, as multiple polls showed. 
Voice of Ukraine 