foreign-flag

[ fawr-in-flag, for- ]
/ ˈfɔr ɪnˌflæg, ˈfɒr- /

adjective

(of a vessel or aircraft) having a registry under a nationality other than one's own: rivalry between U.S.-flag freighters and foreign-flag ships.
(especially of a ship) owned by a national of one country and registered under the maritime laws of another country: Some foreign-flag vessels are actually owned by American shipping companies.