The Korean Central News Agency (KCNA) said that the election "is all the servicepersons' and people's expression of unquestioned support and trust in him," adding that Kim has performed the immortal exploits to shine long in the history of the country.
Kim is also head of the ruling Workers' Party and supreme commander of the 1.2 million-member military.
Analysts had been hoping to glean further information by watching Kim at the Assembly, however the initial reports from Pyongyang's state media did not make clear whether Kim had actually presided over his re-election in person, The Telegraph reported.
The 67-year-old military dictator, who is believed to have suffered a stroke last Aug, capped a week of jubilant domestic propaganda in North Korea as Kim's military leadership sought to capitalise on Sunday's missile test. China and Russia continue to block calls from the US, Japan and South Korea for a United Nations motion censuring the North for breaching a 2006 resolution banning Pyongyang from conducting missile tests.