Haw. Rev. Stat. § 46-9

Any other law to the contrary notwithstanding, any county, including the city and county of Honolulu, may make expenditures of public funds, whenever the funds are available, in order to further the ties of friendship, understanding, and goodwill existing under sister-city relationships entered into by resolution duly adopted by the respective legislative bodies of each county, including the city and county of Honolulu.