Romanian and Bulgarian corvettes Rear-Admiral Eustațiu Sebastian and Bodri were first to dock at the Southern Naval Base.
Later, three more frigates arrived at the port - Spanish Álvaro de Bazán, Turkish F-243 Yıldırım, and Romanian F222 Regina Maria.
All these ships took part in the annual multinational exercises Sea Breeze-2020 under the auspices of NATO.
Ships of NATO's Second Permanent Naval Group (SNMG2) and NATO's Second Permanent Mine Action Group (SNMCMG2) entered the Black Sea two weeks ago to participate in two regional exercises organized by the fleets of Bulgaria and Ukraine.
NATO ships would stay in the Black Sea for 21 days, after which they will leave for further operations.
Earlier head of the US Department of Defense Mark Esper said that the United States should work with NATO partners in order to increase the combat capability of the alliance and deter opponents, including Russia.
Esper called Russia the world's troublemaker - it annexed Crimea, it is waging a war in Ukraine, threatening NATO allies, and sending troops to Syria and Libya.
At the same time, according to Esper, the Russian Federation is a slightly less difficult challenge than China, which seeks to oust the United States from the region and preferably from the world arena.