West hits back with sanctions as Putin orders Russian troops into Ukraine

A pro-Ukraine demonstration near the Russian embassy in Berlin (AP)

World leaders have hit back with sanctions after Russian president Vladimir Putin ordered troops into separatist regions of Ukraine.

Germany made the first big move, taking steps to halt certification of the Nord Stream 2 gas pipeline from Russia – a massive, lucrative project long sought by Moscow but criticised by the US for increasing European reliance on Russian energy supplies.