North Korea's ambassador to Cuba has paid a visit to Cuban President Miguel Diaz-Canel before concluding his mission, the Cuban presidential office said, as Pyongyang is preparing to replace the envoy after Cuba's surprising establishment of diplomatic ties with South Korea.

Diaz-Canel shared a brief video of Friday's meeting with Ambassador Ma Chol-su on X, the former Twitter platform, saying he reassured the ambassador that Pyongyang could always rely on Cuba's support, solidarity and friendship in all aspects.

The president, who visited North Korea twice, also emphasized the brotherhood between the countries.

Ma is reported to have received the Friendship Medal from the president that day in recognition of his diplomatic service in Cuba for the past five years.

The replacement came at a delicate moment, following the surprise announcement of diplomatic relations between South Korea and Cuba on Feb. 14, sparking speculation that the event might have influenced the change of the ambassador.

Given the duration of Ma's service, however, it might just be a routine transfer. Ma was appointed in October 2018, according to reports from the Korean Central News Agency.

Ma's successor has yet to be announced. (Yonhap)