a massive campaign of renaming of placenames was carried out in the German-held part of Lithuania Minor in attempt to erase traces of Lithuanian origin. In 1940, the last Lithuanian newspaper published in Tilsit was closed by the Nazis. German Foreign Minister Joachim von Ribbentrop delivered an ultimatum to the Lithuanian Foreign Minister on 20 March 1939, demanding the surrender of the Klaipėda region to German control. Ribbentrop vowed that if Klaipėda was not ceded to Germany peacefully, it "will be taken by other means if necessary". Lithuania submitted to the ultimatum and, in exchange for the right to use the new harbour facilities as a Free Port, ceded the disputed region to Germany in the late evening of 22 March 1939. Reunion of the Memel Territory with Germany was met with joy by a majority of Prussian Lithuanians. It was Nazi Germany's last territorial gain prior to World War II. The remainder of Lithuania came under occupation by the Soviet Union, then briefly became independent again in 1941 before being occupied entirely by Nazi Germany. During World War II, the Germans operated the in the region, as well as several prisoner-of-war camps for Allied POWs of various nationalities, incl. the Stalag 331 C/I-C and Stalag I-D camps for regular soldiers, the Stalag Luft VI for air force personnel, and Oflags 52, 53, 60, 63 for officers. Groups of Poles expelled from German-occupied Poland were deported by the Germans to forced labour in the region (in the vicinity of Klaipėda and Tilsit). Post-World War II At the end of the war, the local German and Lithuanian population of the former East Prussia either fled or was expelled to the western parts of Germany. The Soviet Union recaptured Lithuania in 1944 and the Memel region was incorporated into the newly formed Lithuanian SSR in 1945 while the remainder of Lithuania Minor was divided between Poland (small parts now forming the Warmian-Masurian Voivodeship) and the Soviet Union (eastern part of the Kaliningrad Oblast). After the death of Joseph Stalin, Nikita Khrushchev offered the Kaliningrad Oblast to the Lithuanian SSR. Secretary Antanas Sniečkus refused this offer. In 2010, a secret document was found which indicated that in 1990, the Soviet leadership was prepared to negotiate the return of Kaliningrad to Germany against payment. The proposal was declined by German diplomats. After the dissolution of the Soviet Union, the Kaliningrad Oblast has become an