The Pentagon has called on Russia to withdraw all vehicles that have crossed into Ukraine:

That news was followed by a relevant question:


https://twitter.com/KevinBarwell/status/502854990680297474

Or else what? There’s always this possibility for a response from the Obama administration:

https://twitter.com/Matthops82/status/502864331147472896

So far the Pentagon says Russia’s refusal to leave Ukraine will lead to “additional costs and isolation”:

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Related:

‘Here. We. Go.’ Reporters witness Russian vehicles ‘slipping across the border into Ukraine’ [photos]