It’s Kyiv not Kiev. A propaganda war on all fronts by multiple actors including non aligned actors.
https://en.m.wikipedia.org/wiki/Kyiv
Both are correct and with 30% of Ukrainians speaking Russian they would pronounce it as Kiev.
This is like nit picking French Swiss saying Genève while German Swiss say Genf. Both are correct.
Unlike Switzerland which has three official languages.
Boils down to that the Ukrainian vs Russian pronunciation is now political...