Bulgaria, Hungary, Romania and Slovakia have signed a joint declaration supporting the idea to link their countries’ gas transmission systems, Hungary’s Foreign Minister P?ter Szijj?rt? announced on Thursday evening.

The idea is to build interconnections of existing gas supply infrastructure that would greatly increase the energy security of all four countries, portfolio.hu quoted Szijj?rt? as saying Hungarian public television M1.

The signing took place in Latvia's capital Riga where the 4th Eastern Partnership summit has brought together top EU officials and leaders of the member states and those of Armenia, Azerbaijan, Belarus, Georgia, Moldova and Ukraine.

The four foreign ministers said that given the need to ensure stable and uninterrupted natural gas supply to Central and East European region they are supporting “the implementation of interconnection and substantial bidirectional capacity of existing infrastructure”, according to a copy of the joint declaration published by euractiv.com.

The foreign ministers of the four countries also expressed support for joint efforts to seek new sources and routes of diversification, adding the document “records political intent only.”

Although the name Eastring doesn’t appear in the joint declaration, the intention to interconnect the gas transmission systems of the four countries cleary refers to that project.

Slovakia has prposed Eastring as an option for diversifying gas supply infrastructure in Europe. Under the proposal, Eastring is to carry gas from the Slovak-Ukrainian border to the Bulgarian-Turkish border, opening opportunities for gas supplies to Bulgaria from Northern and Western Europe.

Eastring could also be connected to a potential gas hub in Turkey, enabling reverse-flow supplies from the Caspian basin, Iraq, Iran, and the Eastern Mediterranean.