FRANKFURT, Germany (AP) — An international financial monitor is warning that wider use of cryptocurrencies by retail shoppers would call for "close scrutiny" by regulators and should be subjected to rigorous oversight.

The head of the Financial Stability Board made the statement Tuesday ahead of the Group of 20 summit June 28-29 in Osaka, Japan.

FSB chair Randal K. Quarles said technological innovation could make the financial sector more efficient and inclusive and that cryptocurrencies do not currently pose a risk to financial stability. He said the FSB and other regulators were working to assess issues such as consumer protection and preventing money laundering.

Cryptocurrency regulation is getting attention from finance officials after Facebook unveiled Libra, a digital form of cash linked to existing currencies.