An Australian man has been arrested and charged with alleged drug offences in Bali, local authorities have confirmed.

Australia and Tuvalu declare there are only a "narrow set of circumstances" where the federal government might trigger a contentious part of the Falepili Union which allows Canberra to veto security arrangements struck by the Pacific Island nation.

David Fifita will depart Gold Coast for Sydney, after telling the Titans he will leave the club at the end of the season.