"Anything that works in this world, will become instantly systemic and will have to be subject to the highest standards of regulations," he said at a conference organised by the European Central Bank in Portugal.

He said regulators would have to look at such currencies' "operational resilience" and their anti-money laundering and counter-terrorist financing procedures.

Carney met Facebook founder Mark Zuckerberg earlier this year.

Facebook unveiled details of its plans for Libra on Tuesday.

(Reporting by Balazs Koranyi; Writing by Rachel Armstrong, editing by Huw Jones)