North Korea may have appointed Pak Yong-sik as the new defense chief to replace Hyon Yong-chol, who is believed to have been executed, an expert said Friday.

Pak, who has been serving as a deputy director of the People’s Armed Forces’ General Political Bureau, was seen saluting leader Kim Jong-un during his trip late last month to a tree nursery aired in a new documentary late Thursday, wearing a four-star epaulet. He was promoted to a three-star general in April 2014.

“When Kim inspects a military unit, its commanders including the defense minister, not the executives of the politburo, usually greet him,” said Cheong Seong-chang, head of unification strategy research at the Sejong Institute.

“Given his appearance at the tree nursery visit and Pak’s promotion to a four-star general last May, it is possible that he has taken over as the minister.”

Hyon was executed on April 30 on charges of treason ― for dozing off while Kim was giving a speech at a military rally days earlier, talking back to the young ruler and complaining about his instructions, according to Seoul’s National Intelligence Service.

He also assumed the ministerial post after being promoted to a four-star general last June.

Though state media has yet to confirm the death of Hyon, he did not appear in the new footage.

The communist country typically removes records and appearances of purged officials from its print and television records.

By Shin Hyon-hee (heeshin@heraldcorp.com)