North Korea's "nuclear war deterrent to cope with and contain various threats from outside is bound to be bolstered up both in quality and quantity continuously and limitlessly," Kim said in a statement carried by Pyongyang's state-run Korean Central News Agency (KCNA).
"The U.S. strategic assets will never find their resting place in the region of the Korean peninsula," Kim added.
The threats she referred to are presumed to be the USS Vermont, which docked at a naval base in Busan to replenish supplies and allow crew members to rest while carrying out its missions in the Asia-Pacific region on Monday.
In a move to demonstrate the isolated country's surveillance and intelligence-gathering capabilities, Kim boasted that North Korea's Aerospace Reconnaissance Agency, an independent spy agency, successfully detected the submarine's arrival.
Pundits speculated that the agency collected information from its spy satellite launched late last year.
