Prokofiev has no proof it's a Ukrainian city (4)
I believe the answer is:
kiev
'a ukrainian city' is the definition.
(I've seen this before)
'prokofiev has no proof' is the wordplay.
'has no' is a deletion indicator.
'prokofiev' with 'proof' removed is 'KIEV'.
'it's' acts as a link.
(Other definitions for kiev that I've seen before include "Ukraine's capital - way of cooking chicken" , "FC Dynamo/chicken ___" , "Ukrainian capital" , "Capital city of the Ukraine" , "Ukrainian city" .)