KIM Jong-un’s sister Kim Yo-Jong is now seen as the “alter ego” of the North Korean dictator as fears grow for the leader’s health.

Kim Yo-Jong, 31, is now thought to be the most important figure in the tyrannical regime after her brother.

4 Kim Yo-Jong arrives to attend a luncheon with South Korean Prime Minister Lee Nak-yeon in Seoul in February 2018 Credit: AP:Associated Press

4 Kim Yo-Jong is seen as her brother's alter-ego, according to one commentator Credit: Reuters

Last weekend, she was reinstated to the party’s powerful politburo according to the state Korean Central News Agency.

She has had a remarkable return to favour after falling out of grace with her brother following her removal from the role and told to keep a low profile following the failure of the Hanoi denuclearisation summit.

She is now thought to be the mastermind behind Kim’s carefully constructed public image, both at home and abroad and is said to have the full confidence of her ruthless brother who is said to have had his own uncle executed for treason.

Attention has now focused on her after fears were sparked about her brother's health after he failed to make an appearance for the 'Day of the Sun' celebrations on April 15.

Kim Jong-un is believed to be in a vegetative state following a botched heart operation, according to reports coming out of South Korea.

The claims come after Chinese medical experts were reportedly sent to treat the North Korean dictator. Speculation began about Reports from South Korean outlets suggested Kim underwent heart surgery on April 12 and was seriously ill.

It is suggested a procedure to insert a stent had gone wrong because the surgeon’s hands were shaking too much.

Last month Kim's sister made her first public statement, condemning South Korea as a “frightened dog barking” after Seoul protested about the North’s recent live-fire military exercise.

She also publicly praised US President Donald Trump for sending Kim a letter in which he said he hoped to maintain good bilateral relations and offered help in dealing with the coronavirus pandemic.

Youngshik Bong, a research fellow at Yonsei University’s Institute for North Korean Studies in Seoul, told The Guardian: “It is revealing that Kim Jong-un permitted her to write and announce a scathing statement about South Korea in such a personal tone.

“He is clearly ready to allow his sister to become his alter ego.”

He is clearly ready to allow his sister to become his alter ego Youngshik Bong, a research fellow at Yonsei University’s Institute for North Korean Studies

Yo-jong has a high profile within the regime both at home and abroad.

Internationally, she has had a high presence during the diplomatic process with both Washington and Seoul and is seen as the “propagandist-in-chief” at home, trying to shine Kim’s reputation as the current head of the dynasty that has ruled the country for three generations.

Leonid Petrov, a North Korea specialist and senior lecturer at the International College of Management in Sydney said: “She has direct access to and strong influence on Kim Jong-un.

“She is not associated with his purges or military brinkmanship, but knows all about them.

“She is a trusted political figure who helps Kim maintain a positive public image when he is dealing with foreigners or South Koreans.”

Yo-jong, was rarely seen in public until 2010, when she was photographed attending a party conference.

But was soon seen as a regular presence in her father Kim Jong-il’s entourage, and was seen mourning after his death in late 2011.

'Propagandist-in-chief'

According to Bong though her closeness to her brother started in the late 1990s when she attended primary school in Berne, Switzerland at the same time as Kim Jong-un.

The pair are said to have lived in a private home, attended to by staff and watched over by bodyguards, according to North Korea Leadership Watch.

“They were virtually in exile together, both knowing what the future had in store for them,” Bong said. “They must have gained a tremendous sense of having a common fate. As a result, she has her brother’s unconditional trust.”

But little is still known about Yo-jong’s life, especially the period from when she graduated from Kim Il-sung University in Pyongyang with a computer science degree in 2007 and when she started to play a role in the ruling party.

She has been credited with arranging her brother’s succession as supreme leader of the country after Kim Jong-il suffered two strokes in 2008 but was first mentioned by the country’s state media in March 2014, when she accompanied her brother during elections for the Supreme People’s Assembly.

Leif-Eric Easley, associate professor of international studies at Ewha University in Seoul said: “The North Korean regime is a family business, and Kim Jong-un appears to place trust in his sister.

“She has demonstrated skills at modernising the brand of the regime, and has some sway over state propaganda. Her most important function is probably as a confidante to her brother.

“But she also has a signalling role because messages from Kim Yo-jong carry more weight than those of an imminently replaceable North Korean official.”

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Petrov said: “She plays a pivotal role in North Korean domestic and foreign policy campaigns because she is one of the main stakeholders in the regime’s survival.”

But, according to Petrov, she is unlikely to adopt the mantle of leader should anything happen to her brother.

He said: “Kim Yo-jong knows how to smooth Kim Jong-un’s initiatives and strengthen his soft power… but she won’t replace the primary decision-maker. North Korea is a Confucian country where seniority and masculinity are respected. She is Kim’s most trusted ally, but no more than that.”

4 Kim Yo-Jong, left, walks ahead of South Korean President Moon Jae-in and Kim Jong-un, right, at headquarters of the Central Committee of the Workers' Party in Pyongyang Credit: AP:Associated Press

4 Kim Yo-Jong, right, arrives at the Dong Dang railway station, Vietnam's border town in 2019, ahead of their second summit with Donald Trump Credit: AP:Associated Press

Mystery surrounds why Kim Jong-un's sister steps in and swaps official signing pen with her own

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