Ukraine's Minister of Energy and Coal Industry Yuriy Prodan is hoping to reach agreements at the upcoming trilateral talks over natural gas supplies with the Russian energy minister and the European Union Energy Commissioner, Gunther Oettinger.

"We want to conclude a very responsible, a very concrete document with clear-cut obligations of the parties and protection of the Ukrainian interests," the minister told Interfax ahead of the talks in Brussels on Wednesday.

It was reported that Ukraine, Russia and the EU have been in talks over normalization of gas supplies since May 2014. Ukraine is challenging the price of gas, and Russia is expecting it to repay the debt for the natural gas consumed in November-December 2013 and in March-June 2014.

Russian gas supplies for Ukraine have been stopped since June 16, 2014.

During the last few rounds the parties overall agreed the so-called "winter packet" involving gas supplies to Ukraine in the next six months. Nevertheless, the legal sealing of the gas price for this period and payment for the gas debt remain outstanding issues.