President Recep Tayyip Erdoğan discussed the quickly evolving developments between Russia and Ukraine with his Ukrainian counterpart Volodymyr Zelenskyy in a phone call on Tuesday.

The two leaders touched upon Russia's recognition of the separatist regions in eastern Ukraine.

Earlier on Tuesday, Erdoğan said Russia's decision to recognize the so-called Donetsk and Luhansk Republics is "unacceptable" and violates Ukraine's sovereignty and territorial integrity.

Russian President Vladimir Putin on Monday signed decrees to recognize the sovereignty of Luhansk and Donetsk, known as the Donbass, at a televised event in which he delivered a fiery speech fundamentally questioning Ukraine's right to statehood.

NATO member Turkey, which shares a maritime border with both Ukraine and Russia in the Black Sea, has good ties with both its neighbors and has offered to mediate the crisis, while warning Moscow against invading Ukraine. Turkey has been closely following the developments and is in close contact with both Kyiv and Moscow. While forging cooperation on defense and energy, Turkey has opposed Moscow’s policies in Syria and Libya, as well as its annexation of the Crimean Peninsula in 2014. It has also sold sophisticated drones to Ukraine, angering Russia.