SEOUL, South Korea — Kim Jong Un's top military official – a key mentor to North Korea's young new leader who had served under his father – has been removed from all posts because of illness, state media said Monday.

But Ri Yong Ho had looked healthy in recent appearances, and that fed speculation among analysts that Kim purged him in an effort to put his own mark on the regime he inherited seven months ago when Kim Jong Il died.

The decision to dismiss the 69-year-old from top military and political posts was made at a Workers' Party meeting Sunday, according to the official Korean Central News Agency. It was not immediately clear who would take Ri's place, and the dispatch did not elaborate on his condition or future.

Daniel Pinkston, a North Korea analyst at the International Crisis Group, was skeptical of the illness claim, in part because of Ri's recent apparent health. He also said Ri won his major promotions at a September 2010 party conference but received none in April, which stirred speculation about the general's future.

"There's a very high probability that it wasn't health issues, but that he was purged," he said, sending a strong signal to anyone seeking to challenge Kim Jong Un – even if Ri never directly defied the new leader.

Ri was vice marshal and chief of the General Staff of the Korean People's Army, making him the nation's top military official behind Kim Jong Un, who rules as supreme commander. In recent years, he also was promoted to key political posts in the Workers' Party that made him one of the top party officials in North Korea.

He had been at Kim Jong Un's side since the young man emerged publicly as father Kim Jong Il's successor in 2010, often standing between father and son at major events.

Ri was at Kim's side at his father's funeral, and accompanied him on his first trips to visit military units after he took power in a pointed show of continuity and military support as Kim sought to shore up the backing of the nation's troops.

Under Kim Jong Il, who ruled under a "military first" policy, the army became a powerful institution in North Korea. Ri held main posts at three crucial institutions: the Korean People's Army, the Central Military Commission of the ruling Workers' Party and the Presidium of the party's influential Political Bureau.

Ri also oversaw an influential Kim Jong Un support group comprising officers in their 50s and 60s whom commanders consider rising stars, according to Ken Gause, a North Korea specialist at CNA, a U.S.-based research organization.

In April, younger officials with economic backgrounds were promoted to key party positions, in line with Kim Jong Un's drive to build up the nation's economy.

In Seoul, Hong Hyun-ik, an analyst at the private South Korean think tank Sejong Institute, said Ri's departure was probably not related to illness but an effort by Kim to put a closer confidant in the top echelons of government. He said he expected more aging officials to be dismissed in coming weeks, calling the move part of a "generational change."

Ri, who had served as chief of the General Staff since 2009 and was promoted to vice marshal in 2010, showed no sign of illness when he spoke in late April at a meeting of top officials marking the 80th anniversary of the army's founding. He was cited in state media as accompanying Kim Jong Un at public events as recently as last week.

North Korea has one of the world's largest armies, with more than a million military personnel in a nation with a population of 24 million.

The Korean Peninsula has remained locked in a state of war and divided by the world's most militarized borders since a truce in 1953 ended three years of fighting.

Animosity on the Korean Peninsula has deepened since a North Korean rocket launch in April that the U.N. called a cover for a banned long-range missile test. North Korea says it was a satellite launch.

North Korea has repeatedly threatened harm to South Korea's president and his supporters in recent months, angry over perceived insults to its leadership and recent U.S.-South Korean military drills that Pyongyang says are a prelude to an invasion.

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Associated Press writer Foster Klug contributed to this report.

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