On the busy streets of Seoul on Friday, residents were bracing for Foundation Day: one of the most important public holidays in neighbouring North Korea and one that is often marked with a show of military force.

Earlier this week, South Korean intelligence sources detected evidence that preparations were underway at a test site. Experts believe that North Korean leader Kim Jong Un may be readying the launch of yet another intercontinental ballistic missile, sending a message that the country not only has a powerful nuclear weapons like the one tested last weekend, but also the means to deliver them to the U.S.

North Korea has mocked American tough talk regarding its tests. After U.S. ambassador to the UN Nikki Haley said North Korea is “begging for war” with its ongoing tests, North Korea’s state-run news agency called her a “prostitute” who is “crazily swishing her skirt” and that the U.S. would “pay a dear price for her tongue-lashing.”

Kang Myung-do defected from North Korea in the mid-1990s. His father-in-law was the North Korean prime minister at the time. Kang says the regime picks public holidays for weapons tests to boast to the world, but also to serve as propaganda to bond North Koreans. Last year on Foundation Day -- a Sept. 9 holiday that marks the 1948 foundation of the country -- North Korea celebrated with a nuclear test.

“Many inside know little of the outer world,” Kang told CTV News through a translator. “They believe their military has the most powerful missiles and nukes and could defeat all.”

That angers other defectors, dozens of whom recently held a protest in Seoul, fearful that war would come and be devastating, especially for those that they left behind.

With a report from CTV News Montreal bureau chief Genevieve Beauchemin