After inspecting an honour guard, Kim, in a black suit, watched the parade pour into Kim Il-Sung Square, accompanied by top military and party leaders, state television showed in a live broadcast.
It was the first time North Korea had shown the missiles - which have a range of more than 1,000km - at a military parade.
Kim did not address the rally, which celebrates the 1912 birthday of his grandfather, Kim Il Sung - North Korea's founding ruler - and which is meant to send an unmistakable message to Washington about the isolated, nuclear-armed North's military might.
Choe Ryong Hae, a close aide to Kim Jong Un, addressed the packed square with a characteristically bellicose warning to the United States.
Amid speculation that North Korean leader Kim Jong-un could be about to order a new nuclear test, a clear message was sent out that North Korea is prepared to act swiftly and in devastating fashion if provoked by the United States. And on his left, the economic policy, bringing North Korea into the modern world.
North Korea is working to develop a nuclear missile that can strike the United States.
On Friday, China's Foreign Minister Wang Yi discouraged the US and North Korea from engaging in "tit for tat" behavior between the two countries after media reports claimed that the Trump administration was positioned to launch a preemptive strike if North Korea appeared to be launching such a test.
Pyongyang has expressed anger over the annual spring military exercises the USA holds with South Korea, which it considers an invasion rehearsal.
China quickly responded to the new jousting in the nuclear hotspot, saying there will be no victor in a war between the US and North Korea.
"If the USA comes with reckless military maneuvers then we will confront it with the DPRK's pre-emptive strike", Han said, calling his country by its official name, the Democratic People's Republic of Korea.
The display raised concerns that North Korea has developed intercontinental ballistic missiles that would allow the country to attack the mainland USA and Europe, according to CNN.
Other weaponry exhibit during the parade included tanks, multiple rocket launchers and artillery guns, as well as a solid-fuel missile created to be fired from submarines.
Saturday's holiday, known as the Day of the Sun, normally includes an vast military parade and synchronized public performances involving thousands of people.
Along with goose-stepping soldiers and marching bands, some weapons analysts have said they believe new types of intercontinental ballistic missiles (ICBM) were among those on display - while acknowledging that the designs may be in their early stages.
Kim emphasizes nuclear weapons as the foundation of his national defense strategy.
The source said: 'News of cadres of the second army corps slandering Kim Jong-un reached all the way to the People's Army's General Political Bureau, and the arrested cadres are to be severely punished'.
"We are ready to hit back with nuclear attacks of our own style against any nuclear attacks", Choe said Saturday.