The European Union will offer better trade ties and easier visa rules to six of Russia's neighbors on Thursday as it seeks their support for oil and gas pipelines bypassing Russia.

The Eastern Partnership — as the EU plan to build closer ties with the six countries is known — kicks off with an inaugural meeting in Prague on Thursday, followed the next day by a separate event focusing on Nabucco, the planned gas pipeline to bypass Russia.

"It's a sort of challenge to Russia," said Boris Shmelyov, director of the Center for Comparative Political Research at the Russian Academy of Sciences. "If it wants to keep these countries in its orbit, it has to come up with a good neighborhood policy of its own."

The Eastern Partnership will embrace the former Soviet republics of Armenia, Azerbaijan, Georgia, Moldova, Ukraine and Belarus — countries that Russia regards as its area of influence. Foreign Minister Sergei Lavrov already criticized the meeting last week.

European Commission President Jose Manuel Barroso and German Chancellor Angela Merkel will offer improved trade ties, simpler visa rules and 350 million euros ($466 million) in aid over four years as part of the Eastern Partnership. The plan also seeks to promote democracy in the six countries.

The EU names as a flagship project to pursue with the eastern partners the development of the "southern energy corridor" — a term that describes all pipelines needed to bring Caspian Sea and Central Asian gas to the EU. The main part of the corridor is Nabucco, said Ferran Espuny, an EU energy spokesman.

Talks to secure commitments to supply gas and build pipelines for Nabucco are progressing well, Espuny said Wednesday.

The EU will hold a separate meeting Friday — dubbed the Southern Corridor Summit — to discuss potential deliveries with natural gas-rich Azerbaijan, Turkmenistan and Kazakhstan and transit countries Georgia and Turkey.

Russia now imports almost all the gas that Turkmenistan produces and is interested in maintaining as tight a grip as possible on supplies from the Central Asian nation. Moscow is also holding talks with Baku to buy Azeri gas starting next year.

As part of the Eastern Partnership, the EU will support Ukraine in improving its aging energy networks, the bloc said in a memo Wednesday. Russia is likely to feel upset about the prospect because it is proposing an alternative scenario to deal with the problem. Prime Minister Vladimir Putin last week suggested resurrecting the idea of creating a consortium consisting of the Russian and Ukrainian national gas companies and European private gas majors to modernize and operate Ukraine's gas transit pipelines.

An investment conference that the EU held in March to help Ukraine upgrade the pipelines, which wasn't part of the partnership, irritated Russia because it ignored its role as the principal user of the system.

Russia initially came down harshly on the Eastern Partnership but later toned down its rhetoric. Foreign Ministry spokesman Andrei Nesterenko struck out at the partnership in March, calling it a "threat" because it made Russia's neighbors choose between Russia and the EU.

Lavrov, however, said last week that Russia was "concerned" over some unspecified comments about Thursday's gathering. He said Russia wanted to believe the EU's assurances that the partnership didn't seek to counter Moscow's influence.

Foreign Ministry spokespeople declined further comment for this article.

"This is not at all an anti-Russian initiative," the EU said in the memo Wednesday. "Russia remains a crucial partner for the EU."

The EU's most senior representatives at the talks will include Barroso, Merkel and Czech Prime Minister Mirek Topolanek, whose country is holding the rotating EU presidency. Armenia, Azerbaijan and Georgia will be represented by their presidents, while Ukraine is sending both the president and prime minister. Belarus will have a lower-level delegation headed by a deputy prime minister, and Moldova, which accused EU member Romania of instigating recent post-election riots, named its foreign minister as delegation chief.

Repeated calls and an e-mail to Jiri Potuznik, the Czech government spokesman for the country's EU presidency, went unanswered Wednesday.

The Eastern Partnership has the potential to make the EU a more formidable rival for Moscow than NATO in the race for influence over the former Soviet republics and their energy resources, Shmelyov said. "It's part of the big geopolitical struggle that has oil and gas at its heart," he said. "Europe is heavily dependent on Russia for energy. We must understand that it cannot and will not last long."