South Korea's top office say that inter-Korean agreements should be implemented to prevent conflict.
The National Security Council convened an emergency session on Sunday to analyze North Korean leader Kim Jong-un's speech as well as the regime's newly unveiled weaponry.
The NSC said it will continue to analyze the details, as well as inspect South Korea's defense capabilities.
It added that any further developments will be monitored, noting that Kim Jong-un had expressed hoped for restored inter-Korean relations.
The NSC also reiterated its call for Pyeongyang to respond to Seoul's proposal for a joint investigationinto the recent killing of a South Korean government worker by the North's troops in waters off the western border last month.