Tuvalu's fishing industry is expected to improve once the construction of a multi-purpose vessel is completed by Japan.
Officials from both governments formalised the agreement to build the ship this month.
Japan's Ambassador, Masahiro Omura, said Tokyo was continuing to support Tuvalu infrastructure development and other areas of the economy.
Tuvalu's Minister for Natural Resources, Puakena Boreham, welcomed Japan's assistance to build the $US4-million vessel, and said she hoped the friendship between the two countries continued.
The relationship is underpinned by Japanese tuna and bonito fishing in Tuvaluan waters.