During 1990, in parallel with internal German developments, the Four Powers—the Allies of World War II, being the United States, United Kingdom, France, and the Soviet Union—together with the two German states negotiated to end Four Power reserved rights for Berlin and Germany as a whole. These "Two-plus-Four" negotiations were mandated at the Ottawa Open Skies conference on 13 February 1990. The six foreign ministers met four times in the ensuing months in Bonn (5 May), Berlin (22 June), Paris (17 July), and Moscow (12 September). The Polish Foreign Minister participated in the part of the Paris meeting that dealt with the Polish-German borders.