On January 26th 1923 Sun Yixian (Sun Yat-sen) and Soviet negotiator Adolph Joffe signed the Sun-Joffe agreement, assuring Soviet support for Sun’s attempts to reunify China:

“Dr Sun Yixian and Mr Adolph Joffe, special envoy plenipotentiary from the Soviet Union, have agreed to issue the following communique. While in Shanghai, Mr Joffe has conducted several conversations with Dr Sun Yixian. Many opinions have been expressed in connection with Sino-Soviet relations. Particularly important are the following points:

1. Dr Sun Yixian believes that the Communist organisation and the Soviet system cannot he adopted in China, since China does not have the conditions to make this adoption a success. Mr Joffe completely agrees with this analysis. Dr Sun further believes that the most urgent problem China faces today is the successful unification of the republic and the completion of national independence. Regarding the undertaking of this important task, Mr Joffe assures Dr Sun that China not only enjoys the deepest sympathy of the Russian people but can also rely on Russia’s assistance and support…

4. Mr Joffe formally declares to Dr Sun that the present government of Russia has never had and will never have any intention of pursuing an imperialist policy in Outer Mongolia or detaching it from Chinese jurisdiction. On his part, Dr Sun concedes that from the point of view of Chinese interest, as well as that of necessity, Russian troops should not withdraw from Outer Mongolia immediately, since the present government at Peking would be unable to prevent the intrigues and hostile actions of the White Russians against the Soviet Union once these were withdrawn. Such a withdrawal will create a situation much more serious than that existing today.

Mr Joffe and Dr Sun part with each other in the most cordial manner. Pending his journey to Japan, Mr Joffe intends to revisit South China before proceeding to Peking.”