In July 2012, Kim was promoted to the highest rank of marshal in the Korean People's Army, consolidating his positions as commander-in-chief of the Armed Forces and Chairman of the Central Military Commission.

[21][22] According to some reports, Kim was described by classmates as a shy child who was awkward with girls and indifferent to political issues, but who distinguished himself in sports and had a fascination with the American National Basketball Association and Michael Jordan.

[25] The Washington Post reported in 2009 that Kim Jong Un's school friends recalled he "spent hours doing meticulous pencil drawings of Chicago Bulls superstar Michael Jordan".

[37][38] The first official image of him as an adult was a group photograph released on 30 September 2010, at the end of the party conference that effectively anointed him, in which he is seated in the front row, two places from his father.

[40][45] On 8 March 2009, BBC News reported that Kim Jong Un was on the ballot for 2009 elections to the Supreme People's Assembly, the rubber stamp parliament of North Korea.

[55] It is believed by some that Kim Jong Un was involved in the Cheonan sinking[56] and the bombardment of Yeonpyeong[57] to strengthen his military credentials and facilitate a successful transition of power from his father.

[58] Kim Jong Un was made a daejang, the equivalent of a four-star general in the United States,[59] on 27 September 2010, a day ahead of a rare Workers' Party of Korea conference in Pyongyang, the first time North Korean media had mentioned him by name and despite him having no previous military experience.

The Korean Central News Agency (KCNA) described Kim Jong Un as "a great person born of heaven", a propaganda term only his father and grandfather had enjoyed.

"[74] He was publicly declared Supreme Commander of the Korean People's Army on 24 December 2011,[75] and formally appointed to the position on 30 December 2011 when the Political Bureau of the Central Committee of the Workers' Party of Korea "courteously proclaimed that the dear respected Kim Jong Un, vice-chairman of the Central Military Commission of the WPK, assumed the supreme commandership of the Korean People's Army".

[76] On 26 December 2011, the leading North Korean newspaper Rodong Sinmun reported that Kim Jong Un had been acting as chairman of the Central Military Commission,[77] and supreme leader of the country, following his father's demise.

[91] In January 2021, the WPK held its 8th Congress, where Kim delivered a nine-hour-long report in which he admitted failures in carrying out the economic plan and lambasted leading officials' shortcomings.

[107] In the same year, Kim Jong Il's personal chef Kenji Fujimoto visited North Korea and said, "Stores in Pyongyang were brimming with products and people in the streets looked cheerful.

[118][119] On 9 January 2012, a large rally was held by the Korean People's Army in front of the Kumsusan Palace of the Sun to honor Kim Jong Un and to demonstrate loyalty.

[122] In November 2012, satellite photos revealed a half-kilometer-long (1,600 ft) propaganda message carved into a hillside in Ryanggang Province, reading, "Long Live General Kim Jong Un, the Shining Sun!

[127] The measures increase the autonomy of enterprises by granting them "certain rights to engage in business activities autonomously and elevate the will to labor through appropriately implementing the socialist distribution system".

[127] North Korean media described the economy as a "flexible collectivist system" where enterprises were applying "active and evolutionary actions" to achieve economic development.

Other objectives of the measures are to increase the availability of domestically manufactured goods on markets, introduction of defence innovations into the civilian sector and boost international trade.

According to the South Korean newspaper The Chosun Ilbo, O was executed by flamethrower for his role in supporting Kim Jong Un's uncle Jang Song Thaek.

[146] A report on the situation of human rights in North Korea in February 2013[147] by United Nations Special Rapporteur Marzuki Darusman proposed a UN commission of inquiry.

[109] At a plenary meeting of the Central Committee of the Workers' Party held on 31 March 2013, he announced that North Korea would adopt "a new strategic line on carrying out economic construction and building nuclear armed forces simultaneously".

[168] In his New Year's Day speech on 2 January 2017, Kim Jong Un said that the country was in the "last stage" of preparations to test-fire an intercontinental ballistic missile (ICBM).

On 30 November 2012, Kim met with Li Jianguo, member of the Politburo of the ruling Communist Party of China and first-ranking vice chairman of the National People's Congress Standing Committee, who "briefed Kim on the 18th National Congress of the Communist Party of China", according to the state's official news agency, the Korean Central News Agency.

[184] The relationship started improving in March 2018, when Kim visited Beijing, meeting with CCP General Secretary Xi Jinping,[185][186] marking his first foreign trip since assuming power.

[202] On 12 June, Kim held his first summit with Trump and signed a declaration, affirming a commitment to peace, nuclear disarmament, and the repatriation of the remains of U.S. war dead.

[211] North Korean foreign ministry further criticized the Trump administration that year for "empty promise[s]",[212] and further took action by demolishing the four-story joint-liaison office building it shared with South Korea on 17 June.

[225] A February 2023 report by the Center for Strategic International Studies (CSIS) stated that after dropping to nearly zero during the COVID-19 era, trade between North Korea and Russia rebounded back to pre-pandemic levels.

[223] In July 2023, Russian Minister of Defence Sergei Shoigu and a Chinese delegation led by Communist Party Politburo member Li Hongzhong arrived in North Korea for the 70th anniversary of the end of the Korean War.

[235] In April 2020, a three-week absence from public view led to speculation that Kim was seriously ill or dead, but no clear evidence of any health problem came to light.

[258] In a 2013 poll, 61.7% of North Korean defectors in South Korea said that Kim Jong Un was probably supported by most of his countrymen, an increase from the 55.7% approval rating for his father in a similar survey done two years earlier.

[276] In July 2024, it was reported by South Korea's spy agency that Kim had regained weight and was suffering from obesity-related health issues, including high blood pressure and diabetes.