North Korea has given no reaction yet to South Korea's establishment of diplomatic relations with Cuba, but the surprise announcement is a blow to Pyongyang that has long boasted brotherly ties with the Caribbean nation.

South Korea forged diplomatic ties with Cuba on Wednesday, making Cuba the 193rd country that South Korea has built diplomatic relations with. That came 65 years after Cuba cut off bilateral exchanges with Seoul following Fidel Castro's seizing of power in a 1959 revolution.

North Korea has not issued any response, but the announcement is an embarrassment to Pyongyang amid expectations that the move could deepen Pyongyang's diplomatic isolation over its nuclear and missile programs.

Since North Korea and Cuba established diplomatic relations in 1960, the two Cold War-era allies have maintained close ties and deepened exchanges based on their shared values of anti-US and imperialist stances.

Late Cuban President Fidel Castro visited North Korea in March 1986 at the invitation of late former North Korean leader Kim Il-sung, the grandfather of the incumbent leader Kim Jong-un.

Cuba has maintained friendly relations with North Korea when Pyongyang has faced diplomatic isolation amid international condemnation over its nuclear and missile programs.

When serving as the president of the Council of State, Cuban President Miguel Diaz-Canel visited Pyongyang in 2018 to meet with the North's leader Kim Jong-un.

North Korea's Kim sent a congratulatory message for three straight days to Diaz-Canel in April 2021 when he was elected the first secretary of the Communist Party of Cuba.

In a message sent in January to celebrate the 65th anniversary of the Cuban Revolution, Kim expressed his expectations that the two nations will further strengthen their bilateral ties. Cuba's new ambassador to North Korea began his duties last month.

The Yoon Suk Yeol administration apparently pushed for the opening of formal ties with Cuba in a low-key manner in consideration of Cuba's longtime relations with the North.

Experts said North Korea may not express overtly its complaints to Cuba, but its relations with Cuba may not be the same as before as Seoul and Havana established the official ties at a time when Pyongyang newly defined South Korea as its "primary foe." (Yonhap)