FILE - Kim Yo Jong, sister of North Korea's leader Kim Jong Un attends a ceremony at Ho Chi Minh Mausoleum in Hanoi, Vietnam, March 2, 2019. Analysts see her as a possible successor to her brother if he were to become incapacitated or die.
FILE - Kim Yo Jong, sister of North Korea's leader Kim Jong Un attends a ceremony at Ho Chi Minh Mausoleum in Hanoi, Vietnam, March 2, 2019. Analysts see her as a possible successor to her brother if he were to become incapacitated or die.

STATE DEPARTMENT - As the United States assesses reports on North Korean leader Kim Jong Un’s health, officials and experts say Washington will continue its sanctions and pressure campaign against Pyongyang. 

“We continue to call on North Korea to avoid provocations, abide by obligations under U.N. Security Council Resolutions, and return to sustained and substantive negotiations to do its part to achieve complete denuclearization‎,” a State Department spokesperson told VOA on Monday. 

FILE- North Korean leader Kim Jong Un waves at parade participants at the Kim Il Sung Square in Pyongyang, North Korea, May 16, 2016.

While South Korea has refuted numerous reports speculating about Kim’s possible death and insisted there are “no unusual movements” in North Korea, analysts are taking interest in the profile of Kim Yo Jong, Kim’s younger sister who is described as one of Kim’s most trusted advisers. 

“Ms. Kim, clearly over the last few years, has slowly been groomed for something bigger,” says Harry Kazianis, senior director for Korean Studies at the conservative think-tank Center for the National Interest. 

Who is Kim Yo Jong?  And why is she seen by some as the most likely successor if Kim Jong Un’s health deteriorates? 

The supreme leader’s sister was recently promoted as an alternate member of North Korea’s ruling Workers' Party's powerful Central Committee Politburo, continuing her ascent in the country’s leadership hierarchy. 

Diplomatic sources took note of Kim Yo Jong's March statement on U.S.-North Korean ties after U.S. President Donald Trump sent a personal letter to Kim Jong Un, seeking to maintain communication and offering cooperation to help the country fight the COVID-19 outbreak. 

She praised Trump for sending the letter at a time when “big difficulties and challenges lie ahead in the way of developing ties” between the two countries, according to the Associated Press, which quoted North Korea’s official Korean Central News Agency. 

The statement is seen by some as a sign of Kim Yo Jong's growing role in U.S.-North Korea relations. 

“No one knows what happens if Kim dies,” writes Sue Mi Terry, senior fellow for Korea Chair of Washington-based Center for Strategic and International Studies, in the Washington Post. 

“The most likely outcome is that Kim’s sister, Kim Yo Jong, would take over,” adds Terry, while questioning whether North Korea’s male-dominated elites would support a young woman as supreme leader.  

Kim Yo Jong has been quite visible around Kim Jong Un in the past two years, including during high-profile meetings between leaders of the U.S. and North Korea, and in watching missile tests alongside her brother.  

She was also pictured riding horses with Kim Jong Un on Mount Paektu – a sacred mountain that is the mythical origin of the Kim dynasty. 

FILE - North Korean leader Kim Jong Un, center, rides a horse as he visits battle sites at Mount Paektu, Ryanggang, in this undated picture released from North Korea's official Korean Central News Agency (KCNA) on Dec. 4, 2019.

North Korea says Kim’s grandfather and father, Kim Jong Il, were born at Mount Paektu, a centerpiece of the North’s idolization and propaganda campaign to highlight the allegedly sacred bloodline of the ruling Kim family. 

“Ms. Kim is clearly moving up the ranks over the last few years – adding more and more top-tier positions to her DPRK leadership resume, something needed if she was to ever take the reins of power,” added Center for National Interest’s Kazianis. 

But “regardless of who assumes power, there are no indications that a successor would pursue different domestic or foreign policies,” says Bruce Klingner, with the conservative think-tank Heritage Foundation. 

“The regime has long emphasized the centrality of nuclear weapons to its national security, and its resistance to negotiating them away,” says the Heritage senior fellow. “A successor may be more deft in reaching out to foreign countries, as Kim Jong Un was, but the underlying objectives and policies would remain constant.” 

FILE - U.S. Vice President Mike Pence, North Korea's nominal head of state Kim Yong Nam, North Korean leader Kim Jong Un's sister Kim Yo Jong, and Japanese Prime Minister Shinzo Abe at the Winter Olympics opening ceremony in Pyeongchang, South Korea, February  9, 2018.

Kim Yo Jong has held numerous high-ranking positions, including first vice director of the Korean Workers’ Party Central Committee, and the first vice director of the Propaganda and Agitation Department. 

She garnered international attention when photographed sitting near U.S. Vice President Mike Pence, during the 2018 Olympics in Pyeongchang, South Korea. 

She is the first member of the ruling Kim family to visit South Korea since the division of Korea at the end of World War II.