The rocket launch boosted public morale, Koh said. "Now people are expecting him to improve the economy and help them live better economically," Koh said. "Kim Jong Un knows that and feels the pressure of meeting that demand."
Kim, who took power after his father's death on Dec. 17, 2011, has asserted control over the government and the military by dismissing its powerful chief Ri Yong Ho. Some other officials who were viewed as more moderate, including Kim's uncle, Jang Song Thaek, were elevated.
South Korean president-elect Park Geun-hye has said she will make efforts in her five-year term to boost aid and engage North Korea.
"If Kim Jong Un is going to engineer a shift from 'military-first' to 'It's the economy, stupid,' he is going to need Seoul's encouragement, and he doesn't have five years to wait," John Delury, an analyst at Seoul's Yonsei University, wrote recently.
He said it's up to South Korea "to unclench its fist first, so that the leader of the weaker state can outstretch his hand."
Kim's speech avoided harsh criticism of the United States, its wartime enemy. North Korea has used past New Year's editorials to accuse the U.S. of plotting war.
In other signs of changes in the country — at least at a superficial level — North Korea also had its first grand New Year's Eve celebration, with residents of the capital treated to the boom of cannons and fireworks at midnight.
In Pyongyang, residents danced in the snow at midnight Monday to celebrate the end of a big year for North Korea, including the 100th anniversary of the birth of Kim Il Sung and the first year of Kim Jong Un's leadership. Fireworks lit up the cold night sky, and people stood in fur-lined parkas, taking photos and laughing and dancing with each other in plazas.
Associated Press writer Kim Kwang Hyon contributed to this story from Pyongyang, North Korea.