French President Emmanuel Macron said Australian Prime Minister Scott Morrison lied to him about canceling the submarine contract, stressing the need for more efforts to rebuild trust between the two countries.

Macron and Morrison participated in the G-20 summit in Rome, the first time they met since Australia canceled a multi-billion dollar submarine deal with France, after a new security alliance with the United States and Britain announced last September.

"I have a lot of respect for your country and a lot of friendship for your people, and I say only when there is respect you have to be honest and you have to act according to this value and in accordance with it," the French president told a group of Australian journalists in Rome.

When asked if he thought Morrison had lied to him, Macron said: "I don't think, I know", confirming that the Australian prime minister had indeed lied to him.

The crisis erupted when the United States announced a new South Pacific security alliance with Britain and Australia, which would need to give Australia access to American technology to build and operate nuclear submarines.

This means that France lost a multi-billion-dollar submarine deal, which it had contracted to supply to Australia, which led to angry reactions in Paris.