North Korea joined in Lunar New Year celebrations on Saturday, beginning with a traditional show of loyalty for the country's former leaders.
Experts have suggested the symbolic footage is the precursor for a major policy announcement.
State media outlet KCNA said it boosted the country's strategic nuclear deterrence. South Korea's defence minister said it was an engine test.
The announcement suggests that the country is preparing to do something to provoke the United States if Washington doesn't back down and make concessions by the end of the year.
North Korea held Taekwondo demonstrations along with other forms of martial arts on Wednesday (September 18) to celebrate the 20th founding anniversary of its International Martial Arts Games Committee (IMAGC).
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Newspapers and television are focussing on the constructive dialogue between the two leaders.
Family members exchanged gifts and dressed in traditional attire.