There were plans of a German-mediated peace between China and Japan, but the fall of Nanking in December 1937 effectively put an end to any mediation that would be acceptable to the Chinese government. Therefore, all hope of a German-mediated truce was lost. In 1938, Germany officially recognised Manchukuo as an independent nation. In April of that year, Göring banned the shipment of war materials to China, and in May, German advisors were recalled to Germany after the Japanese had insisted.