Here's an overview of the coalition's resources and the role it can play in helping secure shipping through the Strait of Hormuz.

- Who has committed? -

France and Britain have been working since March to assemble a coalition to help restore traffic through a channel that carries around 20 percent of the world's oil.

"About 20 countries have made concrete contributions," French President Emmanuel Macron said on Monday, adding four were already "present in the region".

France has committed the largest resources, with its nuclear-powered aircraft carrier the Charles de Gaulle positioned off the Arabian Peninsula since mid-May.

"It can be deployed within two or three days," Macron said, while conceding that the US might not accept the offer of help.

Two minehunter vessels are also nearby and ready to deploy, Defence Minister Catherine Vautrin said on Tuesday.

Britain said in May it was sending a destroyer to the region, and Italy has made two minehunters available.

German Foreign Minister Johann Wadephul has said a minehunter currently in the Mediterranean will take part in mine-clearing operations once it becomes clear that fighting has ended.

- What are the goals? -

International risk specialist Stephane Audrand said the main objective of the mission was "to reassure maritime transport stakeholders so that they agree to send their ships back into the Gulf".

The deployment will aim to remove mines laid by Iran as the US Navy has limited resources for such operations.

The United States has requested "the deployment of mine-clearing capabilities" in the Strait of Hormuz, a European source said on Tuesday, adding that French and German vessels had notably been mobilised for that purpose.

"The more capable countries there are -- and Europeans are quite skilled in mine clearance -- that come on site to clear the waters and ensure there are no mines, the faster shipping will resume," said Audrand, an associate research fellow at the French Institute of International Relations.

According to Britain and France, the warships could also escort some 2,000 tankers and cargo ships waiting to transit out of the Gulf.

"That's a massive logistical undertaking, even in peace time," said Elisabeth Braw, a maritime security expert at the Atlantic Council.

Macron said Oman had already agreed to Western naval escorts.

"If Europeans are involved in one way or another, it is a small victory for them," said Sylvain Domergue, a geographer specialising in maritime security.

- What is the likely impact? -

While US President Donald Trump said the strait would be "completely open" from Friday, a memorandum of understanding between the two nations stipulates the "re-opening of the Strait of Hormuz within 30 days", as quoted by Iran's Mehr news agency.

The memorandum of understanding will not permanently end the war. It buys negotiators another 60 days, extending a state of uncertainty that is bad for business.

The strait remains a major negotiating lever for Tehran, and Iranian officials have said tolls -- or what it terms "service fees" -- could be imposed for ships passing through the crucial channel.

Domergue suggested Iran could be reluctant to allow mine?clearing operations in order to "force ships" to use the waters along its coastline, where a limited number of vessels are currently allowed to transit. On the other side of the strait lie the territorial waters of Oman.

Braw stressed that the agreement announced Monday was "not a permanent peace" deal.

"What really matters is how ship owners view it," she said.

"If they don't have confidence that this is going to fundamentally change things, they will not be queueing up to send their ships out of the Persian Gulf."

Shipping and seafarers' associations said leaders had not yet given enough detail to prompt the ships to start exiting.

They "do not offer sufficient information regarding key aspects such as timings and safe routes", said Jakob Larsen, chief security officer at the shipping lobby BIMCO.

"We still consider it very risky for ships to commence transits at this point."

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