People watch a TV report at a train station in Seoul, March 16, about North Korea's launching of an unidentified projectile. Yonhap

The International Civil Aviation Organization (ICAO) expressed concern Wednesday about North Korea's continued missile launches, stressing the moves posed a "serious risk" to international civil aviation.

The Montreal-based U.N. agency's governing body reiterated its concern over the North's recent "unannounced missile launches which pose a serious risk to international civil aviation," according to a statement posted on its website.