Before the closed-door meeting that lasted around 40 minutes, Merkel congratulated Erdogan over his June 24 presidential election victory.
Erdogan was accompanied by National Defense Minister Hulusi Akar, Foreign Minister Mevlut Cavusoglu and Presidential Spokesman Ibrahim Kalin.
The two-day NATO summit started with the attendance of 29 NATO heads of state and government to make important decisions on the future of the alliance.