Russian President Dmitry Medvedev arrived in Ukraine’s Donetsk on Tuesday, where he will hold talks with his Ukrainian counterpart Viktor Yanukovych and take part in an interregional economic forum.
Apart from the issues of energy and the Customs Union, Medvedev and Yanukovych and their delegations will highlight border interaction, joint research and technology, industrial ties, transportation and the environment.
Energy cooperation between Russia and Ukraine has been marred by a series of spats over supplies, prices and debts. Energy-rich Russia exports 80% of its natural gas to Europe via Ukrainian pipelines.
The Kremlin aide, Sergei Prikhodko, said the case of jailed former Ukrainian premier Yulia Tymoshenko would not be under discussion.
Tymoshenko, 50, was jailed for seven years last Tuesday for exceeding her powers in signing a gas deal with Russia in 2009. Two days later a new case was opened against her in connection with a debt her company owed to the Russian Defence Ministry in the 1990s.