In South Korea, such overtures from Mr. Kim, while not unwelcome, are viewed with considerable skepticism. In his address last year, he indicated that he was open to meeting with President Park Geun-hye of South Korea. But in 2015, the persistent tensions between the countries escalated to the brink of armed conflict, after two South Korean border guards were maimed by land mines. That crisis was alleviated in August; since then, the two sides, which have technically been at war since the 1950s, have held inconclusive talks.

Mr. Kim did not specifically mention the North’s nuclear weapons or long-range missile programs on Friday, though he said the country would continue to develop “more diverse means of military strike of our own style.” He also condemned the joint military exercises held each year by South Korea and the United States.