Trade pact to 'seal Moldova's European path'

But he added: "We see it not as the end of the road. I can say that the association agreement will not constitute the end goal in European Union-Moldova relations. I want to tell you that we believe in the European perspective of Moldova."

EU foreign ministers have made similar statements before.

But Barroso's remarks come amid a drastic escalation in Russia's attempts to stop former satellites from leaving its orbit.

It has annexed Crimea, egged on separatists in Moldova's Transniestria region, banned imports of Moldovan wine and threatened wider economic warfare.

Alluding to a recent incident in which Russia's deputy PM tweeted that he will bomb Moldova's neighbour, Romania, if it blocks his flights to Transniestria, Moldovan PM Iurie Leanca urged Russia to conduct foreign policy "via bilateral meetings, not via Twitter or Facebook".

He added, alongside Barroso, that closer EU ties will help him to reunify his country.

"A stronger European Moldova will … mean we are much more attractive to those who sit on the right bank of the Dniester river, meaning the Transniestria region," he said.

The EU commission chief noted it would be "unacceptable" if Russia tries to "instrumentalise" the 20-year old frozen conflict to stop the trade treaty signature on 27 June.

Both men said Moldova's decision to integrate with the EU is its "sovereign" and "democratic" choice.

Barroso added that Russia's efforts to stop Moldova and Ukraine from signing EU trade agreements is a threat to the "civilised" world.

"It makes no sense to have this idea of the limited sovereignty of other countries," he noted.

"If you accept this principle, then we're heading for trouble not only in the region, but in the world. The principle that one country has the right to veto the decisions of others is an order that we don't think is a civilised order in the 21st century."