The Treaty of Hue was an independently-negotiated treaty between the United States, China, Vietnam and Siam following the Pacific War, negotiated during December 1929 and January 1930, and signed on January 28th, 1930. The agreement settled disputes regarding territory and zones of influence amongst the powers that had contended in the Indochinese Campaign, in particular in regards to Vietnam. Siam claimed small amounts of Vietnamese territory and demanded an end to Vietnamese claims to both eastern Cambodian territory as well as influence over the state, and received both, thus withdrawing amicably from the talks in early January.
China claimed under the held-territory clause of the Hilo Accords that it was entitled to territory in northern Vietnam, as it had defeated Siamese soldiers at Hanoi in 1928 and had agreed upon a ceasefire line north of Hue with the Americans shortly thereafter. However, violent guerrilla warfare and protests against a feared annexation by China derailed these plans, and both Japan and Korea put pressure on China not to annex the territory of a former ally. As such, the American Deputy Secretary of State William G. Carpenter proposed the "three region solution," in which the United States would occupy militarily the southern third of Vietnam around Saigon, the Chinese would occupy the northern third around Hanoi and Hai Phong, and the Vietnamese army would control the middle, around Hue and Da Nang, all whilst the country itself was not partitioned. This led to the 16-year American military occupation of Saigon, as well as sewing the seeds between a Westernized, eventually pro-French South and a pro-Chinese North, which would bubble over into the later Vietnamese Civil War and lead to the formation of the breakaway Republic of Tonkin.