Russian diplomacy at work - as Vladimir Putin lands in Vienna.

The Russian president was on a one-day visit - only his second to an EU country since his country annexed Crimea.

It's a critical one - Austria is now giving its final approval to a controversial Russian gas pipeline through its territory.

The $40 billion South Stream project will carry gas to the centre of Europe - crucially, it'll bypass Ukraine as a transit point.

And that's aroused opposition from within the EU.

Austria's OMV energy company says no matter - Europe still needs Russian gas.

While Russia's Gazprom says it's in constant touch with the EU.

Chief exec, Alexei Miller.

SOUNDBITE (Russian) GAZPROM CHIEF EXECUTIVE, ALEXEI MILLER, SAYING:

"As far as the European Commission is concerned and personally Energy Commissioner Mr. Oettinger, I'm in touch with him all the time, if not daily, at least weekly. That's what our dialogue with the European Commission looks l