Bulgaria’s Prime Minister Boyko Borisov and Russian President Vladimir Putin have discussed over the phone the creation of working groups to review joint energy projects, the government in Sofia announced on Friday.

The working groups will discuss opportunities to resolve problems related to those projects in accordance with the European Union regulations, the government said in a statement on Friday.

Russian news agency TASS reported earlier on Friday that Putin and Borisov ”agreed to intensify interaction within the framework of the Russian-Bulgarian Intergovernmental Commission on economic and scientific-technical cooperation”. It provided no details of the telephone conversation.

The conversation was held at the initiative of Boyko Borisov a day after Sofia revealed that European Commission President Jean-Claude Juncker had sent a letter to Boyko Borisov with replies on issues relating tovarious energy projects relevant to both Bulgaria and Russia, the Bulgarian government said.

These include the abandoned projects for the construction of the South Stream gas pipeline and Burgas-Alexandroupolis oil pipeline, as well as Bulgaria’s plan to build Balkan Gas Hub on its territory.

Boyko Borisov and Vladimir Putin also discussed issues related to nuclear energy, according to the statement.

In his letter to Borisov Jean-Claude Juncker raised the prospect of a possible restart of the abandoned Belene nuclear power plant project, saying that “if Bulgaria decides to build a new nuclear reactor, it must notify such an investment project to the European Commission.”

Bulgaria and Russia have decided to establish a joint working group to consider options for the future of the Belene project after the International Court of Arbitration ruled that Bulgarian state-owned electricity company NEK must pay EUR 550 M to Russia’s Atomstroyexport as compensation for the equipment already manufactured for Belene.

Boyko Borisov and Vladimir Putin also stressed on the need to intensify the work of the Bulgarian-Russian Intergovernmental Commission for Economic, Scientific and Technical Cooperation with the aim to boost trade between the two countries, according to the statement.

The Russian President also expressed hope that the number of Russian tourists visiting Bulgaria will considerably increase in 2016 from last year’s figure of half a million visitors.