As the war progressed and Germany began to retreat further, Japanese ambassador Ōshima never wavered in his confidence that Germany would emerge victorious. However, in March 1945 he reported to Tokyo on the "danger of Berlin becoming a battlefield" and revealing a fear "that the abandonment of Berlin may take place another month". On 13 April, he met with Ribbentrop – for the last time, it turned out – and vowed to stand with the leaders of the Third Reich in their hour of crisis but had to leave Berlin at once by Hitler's direct order. On 7 and 8 May 1945, as the German government surrendered to the Allied powers, Ōshima and his staff were taken into custody and brought to the United States. Now fighting an even more hopeless war, the Japanese government immediately denounced the German surrender as an act of treason and interned the few German individuals as well as confiscated all German property (such as submarines) in Japanese territory at the time. Four months later, on 2 September, Japan had to sign its own surrender documents.