French President Emmanuel Macron said on Sunday that Australia's prime minister Scott Morrison blatantly lied to him about a cancelled submarine deal.

On the sidelines of the G20 summit that took place on October 30 and 31, Australian media asked Macron if he thought Australia's prime minister had been untruthful to him in private meetings.

"I don't think. I know," Macron said.

The French president left no doubt about his position, emphasizing the importance of mutual "respect."

"You have to behave in line and consistently with this value," he said.

Morrison defended himself on Sunday, refuting Macron's claim and denying that he lied to the French president during a private meeting in June.

Macron met Morrison at the G20 and spoke with him on the phone earlier this week, telling him that a "trust relationship" had been broken between France and Australia.

The two have yet to hold formal talks, though the French ambassador is scheduled to meet with Australia's foreign minister in Sydney on Monday.

"I don't agree with that," he said. "It's not true."

"We had dinner together. As I've said on numerous occasions, I explained very clearly that the conventional submarine option was not going to meet Australia's interests," Morrison said.

On Friday, Biden told his French counterpart that Washington had been "clumsy" in its handling of the deal, adding, "We have no better ally than France."

The "stab"

In September, Australia's prime minister abruptly terminated a decade-old multibillion-dollar contract with France to build a new submarine fleet.

Paris denounced the decision as a "stab in the back" and recalled its ambassador, who is only now returning to work in Australia.

The deal's cancellation sparked a bitter feud between France, Australia, and the United States.