Transit passage is a concept of the law of the sea, which allows a vessel or aircraft the freedom of navigation or overflight solely for the purpose of continuous and expeditious transit of a strait between one part of the high seas or exclusive economic zone and another. The requirement of continuous and expeditious transit does not preclude passage through the strait for the purpose of entering, leaving or returning from a state bordering the strait, subject to the conditions of entry to that state. The transit passage may be exercised regardless of the nationality (flag) of the ship, its form of ownership, the merchant or government status of a ship or warship, the private or government status of an aircraft (under the Convention on International Civil Aviation of 1944).
Within such straits (article 37 of UNCLOS), including Arctic straits, all ships and aircraft enjoy the right of transit passage (article 38 of UNCLOS), in accordance with Part III of UNCLOS, which means the right of navigation and overflight solely for the purpose of continuous and expeditious transit of the strait between one part of the high seas or an exclusive economic zone and another part of the high seas or an exclusive economic zone.