Which treaty is it to cut off the three antiquities of Outer Mongolia?

Under the pressure of Russian government and the "good offices" of Japan, France, Britain and Germany, China and Russia started negotiations on Mongolia from191211. 19 13 September, negotiations resumed in Beijing, and 10 signed a statement document between China and Russia on 5 October. In the Declaration, Yuan Shikai's traitorous government recognized the "autonomy" of Outer Mongolia, and announced that it would not engage in the "internal affairs" of Outer Mongolia, and would not station troops, emigrate or send civil and military officials there. In the notes exchanged between China and Russia, it is also stipulated that "China will allow the Russian government to negotiate with the Russian government on any politics and land involving outer Mongolia, and outer Mongolia will also participate in this matter", which actually recognizes Russia's control over outer Mongolia. Russia recognizes China's nominal suzerainty over Mongolia. According to the Sino-Russian statement, the Sino-Russian-Mongolian negotiations were held in Chaktu on September 8, 2004 1965438. The Russian representative called it "mediation" at the meeting, but it was actually making things difficult for the Beijing government representative in China. After more than nine months of negotiations, the China-Russia-Mongolia Agreement (also known as the Chaktu Agreement) was signed in June of 19 15. In fact, this agreement is a further concretization of the Sino-Russian statement document, which stipulates some superficial terms for China to exercise suzerainty in Outer Mongolia.