The People's Republic of China accused India of expansionism and imperialism in Tibet and throughout the Himalayan region. China claimed 104,000 km² of territory over which India's maps showed clear sovereignty, and demanded "rectification" of the entire border.
Relations between the PRC and India deteriorated during the rest of the 1960s and the early 1970s as China–Pakistan relations improved and Sino-Soviet relations worsened. The PRC backed Pakistan in its 1965 war with India. Between 1967 and 1971, an all-weather road was built across territory claimed by India, linking PRC's Xinjiang Uyghur Autonomous Region with Pakistan; India could do no more than protest, however 1971 war with Pakistan, India won a landslide victory. The PRC continued an active propaganda campaign against India and supplied ideological, financial, and other assistance to dissident groups, especially to tribes in northeastern India. The PRC accused India of assisting the Khampa rebels in Tibet. Diplomatic contact between the two governments was minimal although not formally severed. The flow of cultural and other exchanges that had marked the 1950s ceased entirely. The flourishing wool, fur and spice trade between Lhasa and India through the Nathula Pass, an offshoot of the ancient Silk Road in the then Indian protectorate of Sikkim was also severed. However, the biweekly postal network through this pass was kept alive, which exists till today.