French President Emmanuel Macron's unusual decision, according to French Foreign Minister Jean-Yves Le Drian, was made due to the severity of the situation, according to a statement.

Australian Prime Minister Scott Morrison rejected French accusations that his country had not been warned, claiming that he had discussed the possibility of cancelling a 2016 submarine deal with an Italian company during talks in June with President Emmanuel Macron, who was then in office.

Earlier this week, Australia announced that it would cancel a $US40 billion ($A55 billion) deal with France's Naval Group to build a fleet of conventional submarines and would instead, build at least eight nuclear-powered submarines based on technology developed in the US and United Kingdom.