Valley in Arunachal Pradesh. In the winter of 1986, the Chinese deployed their troops to the Sumdorong Chu before the Indian team could arrive and built a helipad at Wandung. Surprised by the Chinese occupation, India's then Chief of Army Staff, General K.Sundarji, airlifted a brigade to the region. Chinese troops could not move any further into the valley and were forced to away from the valley. By 1987, Beijing's reaction was similar to that in 1962 and this prompted many Western diplomats to predict war. However, Indian foreign minister N.D. Tiwari and Prime Minister Rajiv Gandhi travelled to Beijing to negotiate a mutual de-escalation. India and the PRC held eight rounds of border negotiations between December 1981 and November 1987. In 1985 the PRC insisted on mutual concessions without defining the exact terms of its "package proposal" or where the actual line of control lay. In 1986 and 1987, the negotiations achieved nothing, given the charges exchanged between the two countries of military encroachment in the Sumdorung Chu Valley. China's construction of a military post and helicopter pad in the area in 1986 and India's grant of statehood to Arunachal Pradesh (formerly the North-East Frontier Agency) in February 1987 caused both sides to deploy troops to the area. The PRC relayed warnings that it would "teach India a lesson" if it did not cease "nibbling" at Chinese territory. By the summer of 1987, however, both sides had backed away from conflict and denied military clashes had taken place. A warming trend in relations was facilitated by Rajiv Gandhi's visit to China in December 1988. The two sides issued a joint communiqué that stressed the need to restore friendly relations on the basis of the Panchsheel. India and the People's Republic of China agreed to achieve a "fair and reasonable settlement while seeking a mutually acceptable solution" to the border dispute. The communiqué also expressed China's concern about agitation by Tibetan separatists in India and reiterated that anti-China political activities by expatriate Tibetans would not be tolerated. Rajiv Gandhi signed bilateral agreements on science and technology co-operation, establish direct air links, and on cultural exchanges. The two sides also agreed to hold annual diplomatic consultations between foreign ministers, set up a joint committee on economic and scientific co-operation, and a joint working group on the boundary issue. The latter group was to be led by the Indian foreign secretary and