The buildup had spawned widespread speculation that the Kremlin was preparing a wide scale invasion. It already controls large parts of eastern Ukraine – the Donbass region – via proxies it supports militarily and financially.

President Vladimir Putin blasted sanctions, warned the West against crossing “red lines” in their relations with Russia and said Moscow would respond in “rapid and harsh” fashion to  hostile actions.

EU member state Czech Republic and Russia are at the heart of the latest intrigue. Prague on Saturday ordered 14 Russian diplomats to get out within 48 hours, saying Moscow was involved in a 2014 ammunition depot explosion in the country, which, if true, would be an extraordinary ante-up.