In this Oct. 7, 2015 file photo, a worker at a Ukrainian gas station Volovets in western Ukraine controls a valve. (AP Photo)

MOSCOW, May 21 (Xinhua) -- Bulgarian President Rumen Radev on Monday asked Russian Prime Minister Dmitry Medvedev to consider the possibility of direct gas supplies to Europe through the Black Sea.

"Russia has always been a strategic partner in the energy sector as a supplier of natural gas, oil, and nuclear fuel," Radev said when he met Medvedev in Moscow, according to an official transcript of the meeting.

"The security of energy supplies is a very important issue for Bulgaria and the European Union," he said.

Russia currently pumps its natural gas to Europe mainly through Ukraine and Belarus and it attempts to diversify the routes.

During the talks, Medvedev stressed the need for Russia and Bulgaria to intensify trade and economic activities since bilateral trade declined in recent years.

This was Radev's first trip to Russia as Bulgarian president.

Radev will meet Russian President Vladimir Putin on Tuesday at the Black Sea resort of Sochi.