Ukraine has accepted "terms of reference" for European Union monitors who should watch natural gas flows from Russia to Ukraine but talks are still going on with Russia, European Commission President Jose Manuel Barroso said on Thursday, according to Reuters.

"My information is that the Ukrainian side has accepted the terms of reference, the complete terms of reference of European Union observers in terms of transit of gas through Ukraine," he told reporters after meeting central European prime ministers in the Slovak capital.

He said talks were still going on with the Russian side.