 The main objective of the Japanese was to prevent China from importing arms and fuel through French Indochina along the Kunming–Hai Phong Railway, from the Indochinese port of Haiphong, through the capital of Hanoi to the Chinese city of Kunming in Yunnan.Although an agreement had been reached between the French and Japanese governments prior to the outbreak of fighting, authorities were unable to control events on the ground for several days before the troops stood down.Per the prior agreement, Japan was allowed to occupy Tonkin in northern Indochina and effectively blockade China.