Cuba's new ambassador to North Korea has begun his duties, according to the North's state media Thursday, as countries having friendly ties with North Korea have ramped up diplomatic activities in the secretive regime since the opening of its border. North Korean leader Kim Jong-un was presented with the credentials of Cuban Ambassador Eduardo Luis Correa Garcia from Cuban President Miguel Diaz-Canel, according to the Korean Central News Agency (KCNA). The letter of credence was received by Choe Ryong-hae, chairman of the Standing Committee of the Supreme People's Assembly, on Wednesday upon the authorization of the North's leader, it said. North Korea and Cuba have long maintained a close relationship since they established their diplomatic relationship in 1960. North Korea has shut down nine of its diplomatic missions since the second half of last year amid economic difficulties, according to Seoul's foreign ministry. The total number of North Korean diplomatic missions had stood at 44 as of Tuesday. Nicaragua, a country considered to be standing against the United States, is believed to have a plan to open an embassy in North Korea soon. Source: Yonhap News Agency