Russia's natural gas giant Gazprom has told Bulgaria that it will halt its shipments of Russian natural gas to the country as of Wednesday, AFP reported.

"Bulgargaz received a notification today, April 26, that natural gas supplies from Gazprom Export will be suspended starting April 27," Bulgaria's economy ministry said late Tuesday in a statement.

Bulgaria's energy ministry also said Tuesday that its state-owned gas operators Bulgargaz and Bulgartransgaz "have undertaken steps for alternative agreements for natural gas deliveries and for coping with the current situation."

"At present, there is no need for [imposing] any restrictive measures on consumption," it added.

Following the introduction of sanctions against Russia over its invasion of Ukraine, the Kremlin has warned EU member states that their gas supplies will be cut unless they paid in Russian rubles.

Bulgaria's energy ministry did not explicitly say if it has refused to pay in rubles.