France said Friday that it was unable to trust Australia in ongoing talks on forging a trade deal with the EU, after Canberra ditched a deal to buy French submarines in favour of US vessels.

Paris, which has called the Australian decision a "stab in the back", appeared to issue a threat that it could affect far-reaching trade talks.

"We're having trade negotiations with Australia," European Affairs Minister Clement Beaune told the France 24 news channel. "I don't see how we can trust our Australian partners."

The European Commission, which negotiates trade deals on behalf of its member governments, and Australia this spring completed an 11th round of trade negotiations that began in 2018.

The next round of the talks, which cover areas including trade, services, investment and intellectual property rights, is scheduled for the autumn of this year.

The EU is Australia's third-biggest trading partner, with 2020 trade in goods valued at 36 billion euros ($42.4 billion, Aus$58 billion) and at 26 billion euros in services.

France's Naval Group, partly owned by the state, had been chosen to build 12 conventionally powered submarines for Australia, based on France's Barracuda nuclear-powered subs in development.

France has called Australia's decision to cancel a submarine contract a "stab in the back"
France has called Australia's decision to cancel a submarine contract a "stab in the back" POOL / BRENDAN ESPOSITO

The contract was worth around Aus$50 billion when announced in 2016.

But US President Joe Biden and the prime ministers of Australia and Britain announced Wednesday a new defence pact that would see Canberra get a nuclear-powered submarine fleet, a privilege Washington has until now only reserved for Britain.

Beaune added that London's decision to join the AUSUK alliance could cast a lasting pall over its post-Brexit relations with Europe.

"Our British friends told us they were quitting the EU to create a Global Britain," he said. "But we see that Global Britain means a return to the American fold, and a form of accepted subservience."

So far, Beaune added, London has declined on extend Brexit negotiations with the EU to areas of security and defence.

"That's a pity," he said. Maybe it will change in the near future. We hope so."