This is the 38th most frequent Russian word.
украине
"Украине" is the dative or prepositional case of "Украина," meaning "to Ukraine" or "in Ukraine," depending on context.
Here, 'на Украине' is used with the preposition 'на' (on/in), often traditionally used with names of territories or regions in Russian.
Я живу на Украине.
I live in Ukraine.
In this case, 'в Украине' uses the preposition 'в' (in), reflecting a modern preference in Russian for countries and emphasizing involvement within the borders of Ukraine.
Друзья сейчас работают в Украине.
Friends are currently working in Ukraine.
Here, 'Украины' is in the genitive case, reflecting possession or relation, specifically the borders belonging to Ukraine.