over Aksai Chin. In 1956, Chinese Premier Zhou Enlai stated that he had no claims over Indian-controlled territory. He later argued that Aksai Chin was already under Chinese jurisdiction and that the McCartney-MacDonald Line was the line China could accept. Zhou later argued that as the boundary was undemarcated and had never been defined by treaty between any Chinese or Indian government, the Indian government could not unilaterally define Aksai Chin's borders. In 1950, the Chinese People's Liberation Army (PLA) invaded Tibet, which all Chinese governments regarded as still part of China. Later the Chinese extended their influence by building a road in 1956–67 and placing border posts in Aksai Chin. India found out after the road was completed, protested against these moves and decided to look for a diplomatic solution to ensure a stable Sino-Indian border. To resolve any doubts about the Indian position, Prime Minister Jawaharlal Nehru declared in parliament that India regarded the McMahon Line as its official border. The Chinese expressed no concern at this statement, and in 1961 and 1962, the government of China asserted that there were no frontier issues to be taken up with India. In 1954, Nehru wrote a memo calling for India's borders to be clearly defined and demarcated; in line with previous Indian philosophy, Indian maps showed a border that, in some places, lay north of the McMahon Line. Chinese Premier Zhou Enlai, in November 1956, again repeated Chinese assurances that the People's Republic had no claims on Indian territory, although official Chinese maps showed of territory claimed by India as Chinese. CIA documents created at the time revealed that Nehru had ignored Burmese premier Ba Swe when he warned Nehru to be cautious when dealing with Zhou. They also allege that Zhou purposefully told Nehru that there were no border issues with India. In 1954, China and India negotiated the Five Principles of Peaceful Coexistence, by which the two nations agreed to abide in settling their disputes. India presented a frontier map which was accepted by China, and the slogan Hindi-Chini bhai-bhai (Indians and Chinese are brothers) was popular then. Nehru in 1958 had privately told G. Parthasarathi, the Indian envoy to China not to trust the Chinese at all and send all communications directly to him, bypassing the Defence Minister VK Krishna Menon since his communist background clouded his thinking about China. According to Georgia Tech scholar ,