North Korean leader Kim Jong Un supervises a "strike drill" for multiple launchers and tactical guided weapon into the East Sea on May 4, 2019 KCNA | Reuters

U.S. intelligence indicates that North Korean dictator Kim Jong Un recently had cardiovascular surgery, NBC News reported Tuesday, citing American officials. The intelligence also suggests that Kim could be incapacitated, NBC added, citing some of those officials. The update came after the South Korean currency, the won, took a hit following an unconfirmed report that Kim was seriously ill. Kim has been out of public view for several days, according to officials cited by NBC. The new report also seemed to contradict what South Korea's presidential office had told NBC News. "We confirm that Chairman Kim Jong Un is currently touring provincial areas with his close aides and we do not detect evidences to support speculation about his ill health," South Korea's presidential office told NBC News in a statement. "Even North Korea's Worker's Party, military or cabinet aren't showing any special movements such as emergency decree. We believe that Chairman Kim is active as normal as he has been," the office said. Robert O'Brien, President Donald Trump's national security advisor, said in a Fox News interview on Tuesday that the United States is monitoring Kim's status. "We're monitoring these reports very closely," he said. "As you know, North Korea is a very closed society." The White House and the Pentagon did not immediately respond to CNBC's request for comment.

Kim Jong-Un visiting the People's Theatre to mark the 70th anniversary of the founding of the State Merited Chorus in Pyongyang.

Speculation about Kim's health first arose after his absence from the April 15 anniversary birthday celebration of founding father, and Kim's grandfather, Kim Il Sung. Daily NK, a South Korean newspaper that focuses its coverage on North Korea, said late Monday that Kim on April 12 received a cardiovascular procedure at Hyangsan Hospital. The outlet also reported that Kim was recovering in a villa near the hospital. The latest revelation comes after President Donald Trump said Monday that he wants South Korea to pay more for the U.S. military presence there. Seoul and Washington are currently negotiating a new agreement specifying how both countries share the costs of the 28,500 American troops stationed in South Korea. "South Korea is a very wealthy nation. They make our television sets, they make ships, they make everything. And, I give them great credit. We've been defending them for many, many decades," Trump said Monday. "I've gone to them in the past. Last year I went to them, now they're paying a billion dollars a year, and I went to them again and I said, 'Look I'll be back because that's just a fraction,'" he added. "Again, the relationship is great, but it's just not a fair relationship."

The Kim dynasty and North Korea under its youngest leader

North Korean leader Kim Jong Un salutes during a visit to the Ministry of the People's Armed Forces on the occasion of the new year, in this undated photo released by North Korea's Korean Central News Agency (KCNA) on January 10, 2016. KCNA | Reuters

It is unclear how many children Kim Jong Un's father had, it is believed that the former North Korean leader had six children by four different women. Kim Jong Un's mother, named Ko Yong Hui, had a total of three children in the 1980s: two sons, Kim Jong Chul and Kim Jong Un and a daughter named Kim Yo Jong. Kim Jong Un was put forward as the "Great Successor" in 2009 and was made a four-star general the following year. His father, Kim Jong Il, died in 2011 and was believed to be about 70 years old at the time of his death. As planned, Kim took over and was probably around 28 years old. "Some speculated that an uncle and an aunt would serve as co-regents of a kind," explained Jay Nordlinger, author of "Children of Monsters: An Inquiry into the Sons and Daughters of Dictators." The uncle was Jang Song Thaek and in December 2013, "Kim Jong Un left no doubt about who was in charge: He had his uncle arrested and executed. He then killed all the Jang relatives he could get his hands on, no matter how old they were or where they lived." While little is known about the North Korean leader and his immediate family, Kim is believed to be about 36 years old and is married to a woman named Ri Sol Ju. He has at least one child, a daughter, named Kim Ju Ae, who was disclosed to the world by former basketball star Dennis Rodman. If Kim dies, analysts believe that Kim's sister, Kim Yo Jong, will assume control of the nation with a group of loyalists until another successor is named.

Kim Yo Jong, sister of North Korea's leader Kim Jong Un. Jorge Silva | Reuters

In 2018, Kim became the first North Korean leader to cross the 38th parallel to meet South Korean President Moon Jae-In. Both Koreas are technically still at war, as the Korean War of 1950-1953 ended in an armistice, not a peace treaty. Under Kim, the reclusive state has conducted its most powerful nuclear test, launched its first-ever intercontinental ballistic missile and threatened to send missiles into the waters near Guam, a U.S. territory. North Korea is the only nation known to have tested nuclear weapons this century. Since 2011, Kim has launched more than 100 missiles and conducted four nuclear weapons tests, which is more than his father, Kim Jong Il, and grandfather, Kim Il Sung, launched over a 27-year period. North Korea spent most of President Donald Trump's first year in office perfecting its nuclear arsenal, but promised to stop testing of its nukes after the U.S. and international community offered the possibility of relief from crippling economic sanctions.

President Donald Trump makes a statement before saying goodbye to North Korea leader Kim Jong Un after their meeting in the Capella Hotel after their working lunch, on Sentosa island in Singapore June 12, 2018. Susan Walsh | Reuters