US insurance regulators may refuse to apply new global capital rules, arguing the timelines are unrealistic.

The National Association of Insurance Commissioners – which represents state insurance regulators – believes each country must decide if, and to what extent, it will adopt standards being developed by the International Association of Insurance Supervisors.

G20 leaders will consider the rules when they meet in Brisbane in November.

The standards, a response to the global financial crisis, will initially apply to insurers and banks designated globally significant to financial markets, requiring them to hold more capital.

NAIC executives visiting the UK for discussions on the regulations have told media US insurers are already capitalised properly, signalling the industry will not comply.