Bulgaria's President-elect Rumen Radev should consider very carefully his position on Crimea and its incorporation into Russia, incumbent Rosen Plevneliev has said.

"When we continue arguing that Crimea is de jure Ukrainian but de facto Russian because Russia hoisted its flag there and people have to be asked what the future of Crimea should be, the thesis is not shared by a single European leader," Plevneliev has said in an interview with public radio BNR.

His comment is a reference to an interview of Radev aired by France 24 earlier this week in which he reiterates the above-stated position.

"[Incoming] President Radev should consider this thesis very carefully when he assumes office. I will help him by giving my arguments. Above us is the law. Above us is the rule of law. If we want there to be peace in Europe, rules are required and they should be in force for everyone," Plevneliev has told the BNR days before leaving office next Sunday.

The International Criminal Court in November declared Crimea "occupied territory", and no President should contradict a European court if he or she stands up for the rule of law, the outgoing head of state has recalled.

He has also warned that any "work, any comma, any position" of Radev will automatically become "the state position of Bulgaria" once he becomes the sitting President.

While welcoming pragmatism in politics in general, Plevneliev has also advised against pursuing the "realpolitik" of the 19th century, in a reference to his previous comments on the Berlin Congress of 1878, but also to Radev's calls for putting relations with Russia on a more pragmatic footing.