By late 1938, Lithuania had lost control over the situation in the Memel Territory, which had been annexed by Lithuania in the Klaipėda putsch. In the early hours of 23 March 1939, after a political ultimatum caused a Lithuanian delegation to travel to Berlin, Lithuanian Foreign Minister Juozas Urbšys and German Foreign Minister Joachim von Ribbentrop signed the "Treaty of the Cession of the Memel Territory to Germany" in exchange for a Lithuanian Free Zone in the port of Memel that used the facilities erected in the previous years.