Medvevev’s comments came hours after the European Union postponed a planned summit with Ukrainian President Viktor Yanukovych over his refusal to release his top political foe.

“This is an internal affair of Ukraine,” Medvedev said during a joint press appearance with Yanukovych.

“I proceed from a recognition of Ukraine’s sovereignty in respect to its leaders’ decisions,” Medvedev said after talks in the eastern Ukrainian city of Donetsk.

Medvedev said his main concern was that Tymoshenko’s imprisonment on abuse of power charges met all legal standards because any perception of political impropriety could impact Russia as well.

The controversial trial was based on Tymoshenko’s decision to instruct Ukraine’s gas company in 2009 to sign a new deal with Russia that ended a brief cutoff of energy supplies destined for Europe.

“I would like to see the justice now being carried out by Ukraine’s courts to be fully based on Ukrainian legislation, for the sentences issued by the court not to have political or anti-Russian components,” Medvedev said.

The arrest of Ukraine’s former prime minister has seen concern rise in Russia over the fate of the 10-year gas contract but also provoked fury in the European Union where officials cancelled a planned meeting with Yanukovych.

The talks would have focused on an association agreement that mark the first step to Ukraine’s full eventual membership. Yanukovych hoped to have the deal signed by the end of the year.

The Ukrainian president remained vague when commenting on the snub for the first time Tuesday.

“We will always meet with the EU as partners — with members of the European Commission when there is a need and on a bilateral level,” Yanukovych said.