Why are you so certain? Have you heard of the Cobasna ammo depot? It would be mutually beneficial to Ukraine and Moldova if Ukraine were to gain control of that depot and then cede back to Moldova.
It would be like gaining control over an unstable nuclear reactor.
https://www.arnika.org/en/hotspots/moldova/the-largest-illeg...
Cobasna is a huge problem in waiting but it's not an urgent problem.
The real solution is for Russia (as the Soviet Union's biggest successor state) to handle the cleanup and reparations when the region is handed back to Moldova.
And Ukraine obviously supports the Moldovan government’s opposition to that condition, but Ukraine isn’t going to unilaterally invade Moldova to fight Russians while its got plenty of Russians in Ukraine to deal with.