North Korea has warned of a second Korean War should the U.S. continue its expansionist policies in the Asia-Pacific region, the Hermit Kingdom’s Foreign Minister Ri Su Yong  said Thursday. His comments, made at a meeting of the Association of Southeast Asian Nations (ASEAN) in Kuala Lumpur, Malaysia, comes just one week after North Korea’s leader Kim Jong Un threatened to go to war with the United States.

"If the United States continues to strengthen [the U.S.-South Korea] military alliance, engage in large-scale buildup of arms, and use North Korea as an excuse, a Second Korean War is inevitable," said Ri, according to South Korean newspaper Hankyoreh. "In order to protect North Korean sovereignty and its people from a nuclear disaster, we have no choice but to resort to measures of self-defense.”

While the Ri did not say exactly say how the country would commence a potential second Korean war, he did note that the country was gearing up to test a fourth nuclear weapon and that the decision to detonate "depends on U.S. attitudes." The secretive country has conducted a total of three nuclear tests, in 2006, 2009 and 2013. The most powerful so far has been a 7 kiloton underground explosion in February 2013, which is less than half the strength of the bomb dropped on Hiroshima in 1945.

North Korea has complained before about the increasing presence of U.S. troops in the Asia-Pacific region. Pyongyang has increased its military preparedness over the last year, along with regional ally China.

A report from a Chinese government think tank earlier this week highlighted Beijing’s need to expand and improve its Air Force if it is to enforce its superiority in the region and thwart U.S. efforts to establish a presence in the Asia-Pacific area.