The Global Tax Justice Network says some Pacific nations could be given financial assistance to help them adjust from being tax havens.
The network's co-ordinator, John Christensen, has welcomed proposed legislative changes to United States tax laws that would pave the way for sanctions against nations providing tax havens.
The US senate is currently considering the Stop Tax Haven Abuse Bill which would penalise citizens using offshore banking systems as tax havens.
Mr Christensen says some Pacific countries like Nauru have removed their offshore banking services.
But he says others continuing to provide such services need to realise this system only helps a select few rich people while poor people pay more tax.
"Our network is pushing also for the smaller islands that need funds to adjust away from being tax havens to be given compensation so that they can develop new development strategies. But I think they now need to re-think what they're doing. I would like to see the powerful nations that are cracking down on this to recognise that some of the weaker islands and the smaller islands will need help."
John Christensen of the Global Tax Justice Network