Bhutan has no diplomatic relations with its northern neighbor, the People's Republic of China, and is one of the few countries to not recognise or have relations with either China or Taiwan. The border between Bhutan and China has been closed since the invasion of Tibet in 1959, causing an influx of refugees. The border also remains undelineated; in 1961 China published a map that altered the traditional border. Tensions have since lessened, especially after the signing of a 1998 agreement on border peace and tranquility, the first bilateral agreement between China and Bhutan. Despite the lack of formal diplomatic relations, Bhutan has also maintained an Honorary Consul in Macau since 2000 and Hong Kong since 2004.