Russian President Dmitry Medvedev and his Brussels host presided over the signature of an historic deal opening the WTO's doors to Moscow, a move described as "a milestone" by Barroso.
Russia started negotiations to join the World Trade Organisation (WTO) over 16 years ago.
Russia, which had already secured the support of the USA and recently saw a series of obstacles lifted, can now see light at the end of the tunnel.
Lucky number
"This was my 13th summit with Russia and 13 in fact is a lucky number," Barroso said, explaining that the two parties had signed a Memorandum of Understanding to settle bilateral issues regarding Russia's WTO accession.
One of the key obstacles for the Commission was Moscow's plans to put in place a customs union with its ex-Soviet neighbours Belarus and Kazakhstan. But this is no longer seen as a problem in Brussels.
Asked by journalists to comment, Barroso said "yes, of course," Russia could still be a WTO member while also being a member of that customs union. The EU hopes Belarus and Kazakhstan will also join the WTO sooner or later, he added.
Flexibility on Energy Charter?
This was just one of many conciliatory statements made by leaders from both sides. Medvedev signalled new flexibility on the 1991 EU Energy Charter Treaty, which Russia signed in the early nineties but then refused to ratify, citing a desire to protect the country's commercial interests.
Asked to comment on what would be needed to avoid a repetition of gas crises such as those of 2006 and 2009, which cut supplies to the West, the Russian president said: "With regard to guarantees, of course, a good legal base is of primary importance […] We are also ready to work on the basis of the Energy Charter, but not on its present version, but a new version, supplemented and amended, taking into account the Russian proposals and the proposals of other energy supplying countries," Medvedev said.
Openness on climate change
Medvedev also said Russia was determined to make its contribution to tackling the climate change challenge.
Recent unprecedented high temperatures and forest fires in Russia had made even sceptics there understand the extent of the climate change threat, he argued. Alluding to the UN climate summit currently taking place in Mexico, he said: "We need to think what to do later."
Visa flexibility
The EU and Russia are now also engaged on a path that would lead to lifting the visa regime which now exists between Russia and the 27 EU member states.
"I would like to mention the real progress on the visa issue," Barroso said. "This is of great importance to Russia and to the European Union. I know it is very important for Russian citizens and I think our ministers have found an understanding on how to proceed."
He said both sides would now start elaborating a list of common steps and the implementation of those concrete steps would open the way for talks on an "EU-Russia Visa Waiver Agreement".
Russia's ambassador to the EU, Vladimir Chizhov, said recently that the EU's mood on its visa policy towards Russia had changed. A high-ranking diplomat from Eastern Europe told EurActiv that for his country, the visa-free regime with Moscow would be "a return to normalcy," as the countries had a visa-free regime for decades, and the introduction of visas according to EU requirements was seen as an artificial obstacle.
'Partnership for modernisation'
Visa facilitation is now being discussed in the framework of the so-called 'Platform for Modernisation', an initiative launched by Medvedev in Rostov in June 2010.
Barroso described the initiative as "historic" and highlighted Medvedev's ambition to open his country to European values, including the rule of law.
"A comprehensive progress report has been drawn up by our coordinators, as well as a rolling Work Plan," Barroso said. "It contains a set of detailed priorities, from better coordinating business regulations and bolstering the rule of law in Russia to environmental protection. Of course, we have agreed in Rostov that it is not just about technology, but also about a world organisation, including the very important issue, already mentioned, of rule of law."
Outstanding issues
Among issues of concern for the EU cited by Van Rompuy was the need to find solutions to frozen conflicts in Transnistria, a no man's land between Moldova and Ukraine, and Nagorno Karabakh, an Armenian enclave in Azerbaijan.
Van Rompuy also cited South Ossetia and Abkhazia, two regions of Georgia which seceded following the brief 2008 war with Russia. The EU is maintaining monitoring missions to both areas.
