Hitler's strategic thinking delegated Turkey a role of an ally protecting Germany's southern flank against the remnants of the defeated USSR.[12] On 17 March 1941, Hitler stated in a discussion with Franz Halder and Adolf Heusinger that Turkey was to receive territory in the Caucasus (perhaps the Caucasus as a whole) as a reward for helping the Axis, although the territories were to be 'exploited' by Germany.[13][14] In August 1941, Hitler proposed to the Turkish Ambassador in Berlin Hüsrev Gerede that Turkey should annex the Turkic areas of the Soviet Union.[15] In mid-1942, Franz von Papen, the German Ambassador in Ankara, was challenged further by Prime Minister Şükrü Saracoğlu and Foreign Minister Numan Menemencioğlu on the future of the USSR's Turkic minorities.[16] Turkish plans featured the establishment of a series of buffer states along the future Turkish-German border and a sphere of influence extending over these states.[16] Hitler was, however, not ready to make territorial concessions to the country before it fully committed itself to the Axis camp.[16]