Pyongyang's Korean Workers' Party newspaper Rodong Sinmun said Tuesday technical engineers taking part in a contest of skilled workers "showed their enthusiasm" from the start of the competition at the "construction site of the Sunchon Fertilizer Factory."
Selected workers "worked night and day to give joy to our Party" and "showed vitality" during the competition, state media said.
The Rodong article comes nearly two months after Kim cut the tape for completion at the plant, following weeks of speculation he was ill.
State media had said at the time the factory had been "built as a creation of our struggle to achieve prosperity by dint of self-reliance."
The article published Tuesday indicates North Korean engineers may have completed factory construction during the competition, according to South Korean television network SBS' analysis.
The North Korean article mentioned the competition might have begun on or after May 5, following Kim's appearance -- meaning the factory was incomplete when Kim "opened" the plant following his absence.
The North Korean leader's emergence at the plant may have also taken place impromptu. His subordinates may have rushed to stage the event at the Sunchon plant to quell rumors of sickness, according to SBS.
Defectors in the South at the time, including lawmaker-elect Ji Seong-ho, had said Kim might have died; Ji said he was "99 percent" certain the North Korean leader was dead. Ji later apologized for his statement.
North Korea has declined working-level talks with the United States and South Korea, but officials from Washington and Seoul could be resuming in-person meetings.
South Korean news service Seoul Pyongyang News reported Tuesday U.S. Deputy Secretary of State Stephen Biegun could visit Seoul in July.
Seoul's foreign ministry said it couldn't confirm the report on Tuesday.