A delegation of North Korean officials visited industrial facilities and other sites outside of Hanoi less than ten days before the second US.-North Korea summit in Vietnam.  

Kim Chang-son, a close aide to North Korean leader Kim Jong-un, left the Vietnamese government's guest house in Hanoi at around 7 a.m. on Sunday and headed north to the Bac Ninh province, where a smart-phone manufacturing plant for Samsung Electronics and other foreign companies are located. 

There is speculation that Kim Jong-un may visit the industrial facilities in the province during his trip to Vietnam. 

The delegation led by Kim Chang-son also visited Ha Long Bay, a famous tourist destination located east of Hanoi. 

The group is also believed to have seen Lang Son province, which borders China. Some observers said that the delegation might have assessed the possibility of using a special train to reach Vietnam. 

U.S. and North Korean officials, who held a 40 minute meeting on Sunday at the government guest house in Hanoi, are expected to engage in pre-summit talks starting from Monday in order to discuss protocol for the second summit.