Prague - Neither the European Union nor Russia has the right to build a sphere of influence in the former USSR, the head of the EU's executive said on Wednesday on the eve of a major summit with former-Soviet states.

"We believe the time of spheres of interest in Europe is over ... All the countries in Europe are free to choose where they want to be and with whom they want to work," European Commission President Jose Manuel Barroso told the German Press Agency dpa.

On Thursday, the EU is set to launch its so-called "Eastern Partnership" with Armenia, Azerbaijan, Belarus, Georgia, Moldova and Ukraine at a summit in Prague.

The partnership is intended to encourage the six states to bring in pro-democracy and free-market reforms in return for closer ties with the EU on issues such as trade and travel.

EU officials also hope that the initiative will help stabilize the region by encouraging partner countries to work on joint projects, including conflict resolution.

"What we are offering our Eastern neighbours is an increased system of cooperation with them in economic, social and political terms. This is beneficial for them, but we believe also for all the continent in terms of stability," Barroso said.

However, Russian officials have repeatedly criticized the initiative, which they see as the EU's attempt to build a sphere of influence around Russia's borders.

Tensions between Russia and the West are already running high over a series of military exercises which NATO launched in Georgia on Wednesday, and tit-for-tat expulsions of diplomats between Russia and the military alliance in an ongoing spy scandal.