Tuyên Quang Province
There was a territorial dispute near Sino-Vietnamese border. Vietnamese claimed this territory belonged to Tuyên Quang Province and , but was illegally occupied by native chiefdom of Guangxi in final years of Lê dynasty. Quang Trung wrote a letter to Fuk'anggan, required him to return this territory. Fuk'anggan rejected, and replied the border had been delimited. Quang Trung was resentful, from then on, he began to train his soldiers and build many large warships, planning to invade Liangguang. It was said that Quang Trung looked down upon the Qianlong Emperor. He said to his ministers that if given more time to train soldiers, he was not afraid to conflict with China.