"There are those who advocate for the liberation of the Strait of Hormuz by force through a military operation, a position sometimes expressed by the United States," Macron said in South Korea.

"I say sometimes because it has varied, it is never the option we have chosen and we consider it unrealistic," he said.

"It is unrealistic because it would take an inordinate amount of time and would expose anyone crossing the strait to coastal threats from the (Iranian) Revolutionary Guards, who possess significant resources, as well as ballistic missiles, (and) a host of other risks."

He added: "This can only be done in concert with Iran. So, first and foremost, there must be a ceasefire and a resumption of negotiations."

The Strait of Hormuz, a vital shipping route for oil, has been virtually paralysed for weeks by the Middle East war.

Macron also accused Trump of constantly contradicting himself on the conflict.

"You have to be serious. When you want to be serious, you don't say the opposite every day of what you said the day before. And perhaps you shouldn't talk every day," Macron said.