Turkish President Tayyip Erdogan addresses members of parliament from his ruling AK Party (AKP) during a meeting at the Turkish parliament in Ankara, Turkey, November 27, 2018. REUTERS/Umit Bektas

ANKARA (Reuters) - Turkish President Tayyip Erdogan urged his Russian and Ukrainian counterparts in separate phone calls to resolve tensions between the two countries through dialogue and diplomacy, a source in Erdogan’s office said on Wednesday.

Ukraine and Russia have been at loggerheads after Russia captured three Ukrainian vessels and their crews over the weekend in what Kiev fears could be a precursor to a full-scale Russian invasion. Russia accuses Ukraine of plotting with its Western allies to provoke a conflict.

Erdogan held two separate phone calls with Russian President Vladimir Putin and Ukrainian President Petro Poroshenko to discuss the tensions in the Black Sea, the source said.