"The treaty shows that borders can also be changed in a peaceful manner," Belgian Foreign Minister Didier Reynders was quoted as saying in the statement.
Dutch Foreign Minister Bert Koenders praised the deal, signed in Amsterdam in the presence of Dutch and Belgian monarchs, saying it was a "great example of good cross-border cooperation."
The three parcels of land lie on the Meuse river, which runs along their join border. The border was established in 1843 and followed the deepest point of the river.
The river’s course was changed between 1962 and 1980 when it was dug and dammed to improve the connection between the Albert Canal and the Juliana Canal. As a result, parts of Belgian territory have been attached to the Dutch riverside and vice versa, and have been inaccessible by road.