Why is Luxembourg described as a landlocked country?

Luxembourg is described as a landlocked country because it is an independent sovereign state that lacks direct access to an ocean or to a sea that is not itself landlocked.12

Geographically, the country is entirely surrounded by land, sharing borders with Belgium to the west and north, France to the south, and Germany to the northeast and east. While Luxembourg maintains an avenue for the international movement of goods via a port at Mertert on the canalized Moselle River, which connects to the Rhine waterway system, this does not provide the direct oceanic access required to negate its landlocked status.23