North Korean leader Kim Jong-un inspects a flood recovery construction site in North Pyongan Province in this photo provided by the North's official Korean Central News Agency on Sept. 30. Yonhap

North Korea has been quiet on South Korea since August, prompting analysts to suspect that the “unusual” silence could be linked to its plan to amend the country's constitution to ensure that Seoul is seen as the “primary foe,” the Ministry of Unification said, Wednesday.

North Korea has been carrying out a flurry of aggressive acts until very recently, including sending trash-carrying balloons toward South Korea on Wednesday, but refused to issue any statements against Seoul since Kim Jong-un delivered a speech to flood victims in North Pyongan Province on Aug. 9.

This is noticeable given that Pyongyang normally issues statements warning or criticizing South Korea and responds to Seoul's military activities and proposals for unification immediately and negatively.

“North Korea's silence suggests that it won't deal with South Korea in the future. It also wants to send a consistent message to its residents about the ‘two hostile states' stance,” a senior unification ministry official said on condition of anonymity.

North Korea is expected to revise its constitution to define South Korea as its primary foe at the 11th session of the 14th Supreme People's Assembly (SPA), set to take place next Monday.

“North Korea is likely to remove unification-oriented provisions, such as peaceful unification and national unity, newly stipulate the nation's territorial boundaries, including the maritime border, and scrap the Inter-Korean Basic Agreement at next week's key parliamentary meeting,” the official said.

Under the agreement signed in 1991, inter-Korean ties are defined as a “special relationship” tentatively formed in the process of seeking reunification, not as state-to-state relations. The North is expected to abolish the accord as it runs counter to Kim's “two hostile states” paradigm.

Regarding the maritime border, North Korea may either newly stipulate it in a territorial clause in a revised constitution or announce a new borderline in the West Sea without including it as a provision, according to the unification ministry.

“North Korea could ambiguously state it without specifying its location and take legislative steps later to disclose its details,” the official said.

North Korea could unilaterally declare a new maritime border south of the Northern Limit Line (NLL), the de facto inter-Korean maritime border, and carry out provocations. North Korea has never recognized the NLL, demanding that it be redrawn further south.

The ministry also said North Korea could carry out an organizational revamp or personnel reshuffle following the SPA meeting. “We will keep an eye on whether the foreign ministry takes on a bigger role or whether North Korea's Foreign Minister Choe Son-hui gets promoted in regard with Pyongyang's relationships with Russia and the U.S.,” the official said.