Kim sent the message and flowers to Castro on Thursday to mark Castro’s 90th birthday, Workers’ Party newspaper Rodong Sinmun reported.
In his message, the North Korean leader extended “warm comradely greetings” to the former first secretary of the Communist Party of Cuba and credited “Comrade Fidel Castro and Comrade Raul Castro” for “pioneering and dedicating their lives to the Cuban Revolution.”
Kim also described the Revolution as being “carried forward today.”
“Our Party and people believe that comrade Raul Castro, whom we respect, is on the road of struggle for the cause of anti-imperialist independence and socialism,” the North Korean leader said.
“We will never forget and highly appreciate [Castro’s] great contribution made in strengthening and developing the true comradely unity and friendly, cooperative relationship between our two parties and our two countries,” Kim said.
The North Korean head of state also said he “sincerely wishes that Comrade Raul Castro, an elder of the Cuban Revolution, a close friend of the North Korean people, and a comrade in the revolution, stay healthy and happy.”
Castro succeeded brother Fidel as leader in 2011 and resigned in April. When President Miguel Díaz-Canel was appointed leader of Cuba’s Communist Party, Kim sent his “most heartfelt congratulations.”
In 2015 a Cuban delegation visited Pyongyang, and in 2018 Diaz-Canel traveled to Pyongyang for a three-day visit, when Kim gave him a red-carpet welcome.
Kim has been missing from public life since May 6, when he was last seen attending a performance of military families.
South Korean analysts said that Kim is “preparing for his next move” after the U.S.-South Korea summit, local network MBN reported Friday.