The EU's Lisbon Treaty has come into effect following ratification by all 27 member states.
The treaty reforms the working of the union and increases the European Parliament's powers.
The head of the EU delegation to Russia, Fernando Valenzuela, believes the new treaty will boost Russia-EU cooperation.
“[The Lisbon Treaty] should make us more democratic, more efficient and better fit to act in the world stage. In that sense this also will bring the elements for strengthening bilateral relations with Russia. We sincerely think that this treaty will make us a more reliable and stronger partner of Russia,” he said.