Kremlin envoys said the talks were 'very disappointing' in Vienna Thursday and next steps would be reached after they brief Russian President Vladimir Putin  

Deputy Foreign Minister Sergei Ryabkov would 'neither confirm nor exclude' the possibility that Russia could send military assets to Cuba and Venezuela 

Ryabkov said it was up to the United States how the situation would play out 

But State Secretary Antony Blinken put the onus on Putin in an MSNBC interview

On Weds. Russia demanded a guarantee that Ukraine will never be let into NATO

But this was unanimously rejected, as were other demands made by the Kremlin

NATO chief Jens Stoltenberg warned there was now 'a real risk of a new armed conflict in Europe' with Russia having built up troops on Ukraine's border 

Meanwhile, Russia cranked up its war games with live-fire exercises