"We will regard the naval blockade of the United States and its followers as an act of violence against the sacred sovereignty and dignity of the Republic of Korea and as another public declaration of war," the Rodong Sinmun, North Korea's ruling communist party newspaper, said in a commentary.

The paper added, "If we see a small movement to put the maritime containment into practice, we must be prepared to follow our immediate and ruthless self-defensive response."

The Korean Central News Agency, the North's official newswire service, filed a similar report in English on Friday saying, "The US moves for sea blockade can never be tolerated as they constitute a wanton violation of the sovereignty and dignity of an independent state."

Talk of a possible maritime blockade has also emerged in academic circles though Seoul has reiterated its opposition to any military options, including a pre-emptive strike, to address the nuclear standoff. (Yonhap)