This is an escalation that looks like it was intended to signal nuclear readiness and that their nuclear saber rattling isn't a joke. The US claims this didn't happen. Russia hasn't said either way. Ukraine could escalate in retaliation. But I don't think there is any escalation path they can take that would move them into a stronger negotiating position without Russia simply responding much more forcefully.
with all this stuff i think, what the hell... ukraine is a big country by land and a lot of land and a lot of wheat and minerals but it's really nowhere near as well equipped for war as russia is... and russia has the largest territory on the planet, and more resources available than anyone but i remember in 2014 when this actually all started there are people who just want to see as many people as possible die