Updated 11:52 PM ET
(AP) PYONGYANG, North Korea - North Korean leader Kim Jong Un spoke publicly for the first time Sunday, just two days after a failed rocket launch, portraying himself as a strong military chief unafraid of foreign powers during festivities meant to glorify his grandfather, North Korea founder Kim Il Sung.
The young new leader, dressed in a dark Mao suit, appeared confident and calm as he read from notes before tens of thousands of people gathered in Pyongyang's main square during meticulously choreographed festivities honoring the late Kim Il Sung, whose 100th birthday was Sunday.
Kim Jong Un's words mirrored what North Korea regularly says in its state media, but there was symbolic power in the images of the new leader, who is believed to be in his late 20s, addressing the country on state TV and then watching and often laughing and gesturing in relaxed conversation with senior officials as a parade of North Korean military troops and hardware marched by.
In the speech, he made it clear that the military will continue to have a dominant role in running the country, just as it did under his father and former leader Kim Jong Il, who died in December. He called for strengthening his father's "military first" policy by placing the country's "first, second and third" priorities on military might.
Although the North endured an embarrassing failure Friday when its much-anticipated launch of a long-range rocket broke into pieces over the Yellow Sea shortly after liftoff, the address Sunday was seen as an expression of confidence by the young leader and a signal meant to show that he is firmly in control. It also provides a marked contrast with Kim Jong Il, who didn't make public addresses during his later years, even at major events.
Outside analysts have raised worries about how the new leader, who has been seen but not publicly heard since taking over after Kim Jong Il's death, would govern a country that is building a nuclear weapons program and has previously threatened Seoul and Washington with war.
Kim Jong Un said the era when nuclear arms could be used to threaten and blackmail his country was "forever over."
He said his country had built a "mighty military" capable of both offense and defense in any type of modern warfare
"Superiority in military technology is no longer monopolized by imperialists," he said.
The United States and other countries had questioned whether there would be a smooth transition of power in North Korea when Pyongyang announced in mid-March that it would launch a long-range rocket despite a February deal with the U.S. in which it promised a moratorium on nuclear and missile testing in return for food aid, said one North Korea expert.
Kim Jong Un's speech Sunday was "an expression of confidence," said the analyst, Kim Yeon-su of Korea National Defense University. "Kim Jong Un is trying to dispel lingering doubts about his grip on power."
By trumpeting the might of his country's military in his first public speech, Kim Jong Un is also sending a strong message that he sees "himself as more of a military leader than a civilian one," Kim Yeon-su said.
After Kim's speech, thousands of troops goose-stepped through the square in tight formation, saluting the young leader as they passed. North Korea's 1.2 million-man army is one of the largest in the world. Rows of infantry, tanks and heavy artillery were followed by a wide array of increasingly large truck-mounted missiles. The parade culminated in a roaring fly-by of five fighter jets.
The speech was a good "first impression for his people and for the world," said Hajime Izumi, a North Korea expert at Japan's Shizuoka University. "He demonstrated that he can speak in public fairly well, and at this stage that in itself more than what he actually said is important. I think we might be seeing him speak in public more often, and show a different style than his father."
North Korea defied the U.S. and others Friday by firing a long-range rocket that space officials said was mounted with an observational satellite despite warnings against pushing ahead with the provocative launch. Washington and others say it was a covert test of long-range missile technology.
Hours after the rocket crashed into the sea, the country made an unusual admission of failure, but Kim did not mention the launch in his remarks Sunday.
International condemnation of the rocket firing was swift, including the suspension of U.S. food aid, and there are worries that the North's next move could be an even more provocative nuclear test.
The U.N. Security Council denounced the launch as a violation of resolutions that prohibit North Korea from developing its nuclear and missile programs. The council imposed sanctions on North Korea after its first nuclear test in 2006 and stepped up sanctions after its second in 2009.