While the top-brass visit is concerned loosely with the planning of an EU-Russia summit this spring, the commission said Friday a "whole series of questions" would be addressed, including the WTO candidacy and enlargement which have ratcheted up tensions between the two sides.

Russia has shown considerable nervousness at the EU's expansion on May 1 to take in 10 mostly former Soviet satellite states once beholden to Moscow, which would bring the future 25-member bloc up to its borders.

Negotiations between the current EU presidency, Ireland and Russia failed this week to modify their trade-based Partnership and Cooperation Agreement (PCA) to encompass the 10 future members -- a change which Moscow fears will result in a loss of preferential trade tariffs there.

"We have succeeded in covering 95 percent of the questions (concerning the PCA). We have found solutions, but we are pursuing discussions on two issues," Arancha Gonzalez, spokeswoman for Trade Commissioner Pascal Lamy, said on Friday.

The spokeswoman said discussions -- concerning the rights of ethnic Russians living in incoming EU states and the status of the Russian enclave of Kaliningrad -- had taken place in Brussels on Wednesday and were ongoing on Thursday. "They will continue next week", she said.

The European Union has also mounted resistance to Moscow's WTO bid, worrying that the domestic natural gas subsidies offered within Russia would unfairly help Russian companies produce cheap goods for sale on European markets.

In addition to Lamy, Prodi will be accompanied to Moscow by: External Relations Commissioner Chris Patten; Enlargement Commissioner Guenter Verheugen; Justice and Home Affairs Commissioner Antonio Vitorino; Transport Commissioner Loyola de Palacio; Environment Commissioner Margot Wallstroem; and Research Commissioner Philippe Busquin.

Russian Foreign Minister Sergei Lavrov, after meeting his Irish counterpart Brian Cowen in Dublin on Wednesday, said he was confident both sides would reach agreement in the two weeks remaining before the EU enlargement.

The goal for the diplomats now is to strike a formal agreement which could be presented at a meeting of European foreign ministers in Luxembourg on April 27.

The meeting will be the last between the EU ministers before the bloc welcomes the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Slovakia and Slovenia, plus Cyprus and Malta into its ranks.