German Chancellor Angela Merkel (R) talks with a policeman during the German Federal Government Open Day in Berlin, Germany, on Aug. 18, 2019. Major political institutions of German Federal Government, including German Chancellery, opened to the public on Saturday and Sunday. (Xinhua/Shan Yuqi)

German Chancellor Angela Merkel (C) attends the German Federal Government Open Day in Berlin, Germany, on Aug. 18, 2019. Major political institutions of German Federal Government, including German Chancellery, opened to the public on Saturday and Sunday. (Xinhua/Shan Yuqi)

German Chancellor Angela Merkel (in red) speaks to visitors during the German Federal Government Open Day in Berlin, Germany, on Aug. 18, 2019. Major political institutions of German Federal Government, including German Chancellery, opened to the public on Saturday and Sunday. (Xinhua/Shan Yuqi)

Visitors ride on police motorcycles during the German Federal Government Open Day in Berlin, Germany, on Aug. 18, 2019. Major political institutions of German Federal Government, including German Chancellery, opened to the public on Saturday and Sunday. (Xinhua/Shan Yuqi)

A man visits a fighter jet at the German Ministry of Defense during the German Federal Government Open Day in Berlin, Germany, on Aug. 18, 2019. Major political institutions of German Federal Government, including German Chancellery, opened to the public on Saturday and Sunday. (Xinhua/Shan Yuqi)

Members of German Bundeswehr introduce equipment to visitors during the German Federal Government Open Day in Berlin, Germany, on Aug. 18, 2019. Major political institutions of German Federal Government, including German Chancellery, opened to the public on Saturday and Sunday. (Xinhua/Shan Yuqi)

A boy tries on military equipment at the German Ministry of Defense during the German Federal Government Open Day in Berlin, Germany, on Aug. 18, 2019. Major political institutions of German Federal Government, including German Chancellery, opened to the public on Saturday and Sunday. (Xinhua/Shan Yuqi)