In parliamentary systems, elections cannot be delayed, but they can be held earlier, (1) at the discretion of the ruling majority, (2) in the event of a hung parliament or (3) on the eve of an important national decision.
The Parliament isn’t able to do their duty, this matters in Ukraine (not Russia where the Duma is a rubber stamp for Putin). Hopefully some good people in Ukraine can elect the kind of statesmen they need at a time like this