塘沽協定
Since 1931, Japan had been provoking numerous incidents and violating Chinese sovereignty. The Tanggu Truce established a demilitarized zone between Japanese-occupied territories and North China in 1933, but conflict continued unabated by proxy armies in Inner Mongolia. However, with the appointment of Kōki Hirota as Foreign Minister of Japan, the Japanese civilian government attempted to improve Sino-Japanese relations. On 22 January 1935, Japan announced a policy of nonaggression against China. In response, the Chinese government's Wang Jingwei announced a suspension of the Chinese boycott of Japanese goods, and both countries agreed to upgrade relations to the ambassadorial level.