Talks about technical and legal aspects of the preparation for the reverse gas flow from west Europe to Ukraine are to be continued, Slovak Economy Minister Tomas Malatinsky said on Tuesday.

He made the remarks after a meeting with Ukrainian Energy and Coal Industry Minister Yuri Prodan, European Commission officials and representatives of infrastructure companies Eustream and Ukrtransgaz in the border town Velke Kapusany.

"The trilateral talks between the European Commission, Slovak and Ukrainian sides are not completed yet. I'd say that now we find ourselves in the mid-phase," Malatinsky said.

"Some potential solutions with respect to the reverse flow have been submitted; we're also drafting another alternative... discussion is still pending. Maybe the Memorandum will be signed in the following days, but not today," he added.

Ukraine prefers to see the existing Slovak pipeline to be used for the reverse gas flow rather than the alternative of building a new pipeline in Vojany exclusively for the reverse flow.

Prodan hasn't specified the amounts of gas Ukraine would like to receive from Slovakia following the agreement between all parties involved.

European Commission Deputy Head of Cabinet Klaus-Dieter Borchardt welcomed the proposal tabled by the Ukraine at the meeting.

"The Vojany solution won't secure gas supplies to Ukraine until next winter," said Borchardt. He added that Ukrainian proposal needs to be submitted for comprehensive analysis first.

According to Malatinsky, the reverse flow of gas supplies to Ukraine from the west and from Slovakia isn't easy to execute and there are some technical specifications that need to be resolved.

"There is also a problem in terms of the contract, because this route serves for delivering gas from Gazprom through Ukraine to Europe," said Malatinsky.

"We want and we are ready to help Ukraine, but we have to take into consideration the Slovak and European interests, because that gas flows to Europe," he added.

In the meantime, Slovakia has already started to work on the launch of reverse gas flow to Ukraine. Slovak Ministry of Economy issued a license for this to Eustream on Monday.

Kiev began emergency talks on assistance with the gas supplies with its neighbors in the European Union (EU) after Russian gas company Gazprom in early April increased the gas prices for Ukraine to almost double the original price.

At the moment, Ukraine, which is in a deep economic crisis, covers half of its gas supplies from Russia.