However, the boundary between North Korea and the People's Republic of China is still contested, in spite of the 1963 agreement. In response to North Korea's perceived lack of support in the Sino-Soviet split, China demanded that North Korea cede its portion of the peak of Mt. Baekdu to China, and between March 1968 and March 1969, a number of border clashes between North Korean forces and Chinese forces took place in the Mt. Baekdu region. PR China wanted to restore Gando Convection boundary. Chinese demands for the rest of Mt. Baekdu were eventually dropped in 1970 in order to repair relations between North Korea and China. China has recognized North Korea's sovereignty over some 80% of the islands in the Yalu/Amnok and Tumen Rivers, and also accepted North Korea's control of some 90% of the mouth of the Yalu/Amnok River. While not openly discussed anymore, it would appear that the 1963 agreement is only something of a framework and not exactly a binding contract for either North Korea or China.