Bulgaria and Romania could send fighters after Russia's Deputy PM Rogozin while he was traveling to Transnistria via Bulgarian airspace, as he wrote on Twitter.

Dmitry Rogozin said he had been informed by the pilot that Bulgaria's air-control personnel had asked whether the "blacklisted passenger" was on board.

"They were going to send up interceptors," Rogozin added.

On Thursday he was forced to go around Ukraine to visit Transnistria after Kiev announced it was closing Ukrainian airspace for his plane.

Also via Twitter, he wrote on that day he would have to use Bulgarian and Romanian airspace to make it to the enclave of Transnistria's capital Tiraspol.

The Deputy PM is among those blacklisted by both the EU and the US over Russia's actions in Ukraine.

A travel ban is in place for him within EU members' territory. Rogozin is President Putin's special envoy to Transnistria for Victory day commemorations, according to the Russian Ambassador in Moldova, who was summoned by the country's Foreign Ministry to give his account for the high-profile visit.

Transnistria is a Russian-populated enclave in Moldova which is not recognized even by Moscow, but has sent requests to the Kremlin asking to join the Russian Federation.

Bulgaria's Defense Ministry has not commented on the issue, but its reaction seems to have been a routine, as fighter jets have been frequently scrambled in the past weeks in response to Russian reconnaissance flights near Bulgarian airspace over the Black Sea.