France, May 4 -- Speaking on Monday as he arrived at the 8th summit of the European Political Community in Armenia, President Macron struck a cautious tone over plans unveiled by his US counterpart Donald Trump to free ships stranded for two months in the Iran-controlled Strait of Hormuz.

"I don't know what this initiative is," Macron said bluntly, signalling unease in Paris over the framework and objectives of the proposed operation.

The announcement from Washington was swiftly met with a warning from Tehran, with Iran's military command stating that US forces would face attack if they attempted to approach the strategic waterway - a vital artery for global energy supplies.

Trump has said the United States will launch an effort on Mon...