He did not speak, but did send a message by locking fingers and raising hands with Li Zhanshu, a special envoy sent by Chinese President Xi Jinping.
That's a big departure from February's parade, when it displayed its Hwasong-15 intercontinental ballistic missile, believed capable of reaching the US, and a number of other formidable missiles and the erector-launchers used to fire them off from remote locations.
The slogans - one of which said "all efforts on economy" - are in line with Kim's new political priority outlined earlier this year before he met Trump.
Although North Korea stages military parades nearly every year, and held one just before the Olympics began in South Korea in February this year, Sunday's parade came at a particularly sensitive time.
"Just moments ago they put on that he said very strongly that we want to denuclearize North Korea during President Trump's tenure. just said it, just said it", Trump said at a campaign rally in Montana.
North Korea's leader Kim Jong Un (C) waves as he stands beside China's Chairman of the Standing Committee of the National People's Congress Li Zhanshu (centre R) during a "Mass Games" artistic and gymnastic performance at the May Day stadium in Pyongyang on September 9, 2018.
Visiting media representatives in recent days have been invited to tour cutting-edge facilities and historical sites, as Kim has pledged to boost the country's economy instead of developing nuclear weapons and ballistic missiles. So it's possible Kim might choose to display them but give the missiles a lower profile if he makes his usual address just before the parade begins.
Foreign dignitaries and officials have begun arriving Pyongyang on the eve of North Korea's 70th founding anniversary, amid a deadlock in denuclearisation negotiations with the United States.
China's president also sent a message expressing "the unshakable policy of the Chinese party and government to successfully defend, cement and develop the bilateral relations" between the two nations, according to Korean Central News Agency.
The parade comes at a sensitive time in the region.
"All Koreans should join forces to accomplish unification in our generation", said an editorial in North Korea's party newspaper Rodong Sinmun. This spectacle of human art, in which thousands of carefully drilled performers hold up colored placards that, in combination, create a series of shifting images, is a flagship specialty of North Korea.
The parade came at a delicate time, as Kim presses for a peace declaration to formally end the war North Korea and China fought against USA -led forces from 1950-53. He claims to have perfected his nuclear arsenal enough to deter USA aggression and devote his resources to raising the standard of living.
The mass games involve tens of thousands of people holding up placards or dancing in precise unison and are meant to be a display of national unity.
North Korea routinely uses major holidays to showcase its military capabilities and the latest developments in missile technology.
The past two big anniversaries of North Korea's founding, in 2008 and 2013, did not feature the Korean People's Army, only the civil defense units, which are officially called "Worker Peasant Red Guards".