Kim Jong Un had not been seen in public for 36 days, fueling speculation about his health.
But North Korea's leader attended a meeting with military officials on Monday, reports said.
He was discussing war strategies as tensions rise around the Korean peninsula, the reports said.
North Korean leader Kim Jong Un abruptly reappeared after 36 days out of the spotlight as he ordered his country to "prepare for war," according to multiple reports.
Kim was photographed presiding over a meeting of the central military commission of the ruling Workers' Party on Monday, Reuters reported.
His presence marked the first time he was back in the public eye after more than a month for reasons that have not been made public.
His disappearance raised questions about his health from multiple news outlets. Kim's Jong Un's longest-ever break from the spotlight was in 2014, when he was not seen for 40 days.
In the meeting on Monday, Kim and his military officials "discussed in depth the major military and political tasks for 2023 and the long-term issues concerning the orientation for army building," The Korea Herald reported, citing the official Korean Central News Agency (KCNA).
The meeting comes as Pyongyang prepares to mark the 75th founding anniversary of the Korean People's Army on Wednesday, which will likely be celebrated with a military parade. Kim is expected to be there, NK News reported.
Tensions have been rising around the Korean Peninsula after Pyongyang condemned planned joint military drills between its rival, South Korea, and the US in the area.
A spokesperson for North Korea's Foreign Ministry said the expansion of the military drills announced by the US last week threatens to turn the peninsula into a "huge war arsenal and a more critical war zone," the Associated Press reported.
Pyongyang is prepared to counter with the "most overwhelming nuclear force," the statement added.
South Korea has said it was monitoring increased military activities in Pyongyang, Reuters reported.
Before reappearing on Monday, Kim was last seen in another government meeting on January 2, where it was announced that a top military official, Pak Jong Chon, had been fired and replaced, Reuters reported at the time.
