Turkey has decided to restrict access for Russian warships to Turkish-controlled straits leading to the Black Sea, Bloomberg reports, citing two Turkish officials with knowledge of the matter..

Turkish President Recep Tayyip Erdogan has indicated before that he will "exercise" the authority over the straits granted to Turkey at the 1936 Montreux Convention.

The straits under Turkish control give the Russian Black Sea fleet access to the Mediterranean.

Now, Ankara has decided to prevent Russian warships from attempting to enter the Black Sea, except for those returning to their home bases.

Turkey believes that there is no need to make a formal announcement after it has already deemed the invasion of Ukraine to be an act of war, one of the legal requirements for using the prerogative under the Montreux Convention.

The Turkish decision, however, may not have a significant impact on the unfolding war, notes Teneo Intelligence, cited by Bloomberg. This is because, prior to Putin's order to invade Ukraine, several Russian ships were repositioned to the Black Sea.

"Not a single Russian ship has crossed the Bosphorus and Dardanelles straits since the beginning of the conflict in Ukraine," Teneo reports.