A United Nations agency said Tuesday that a plan is underway to evacuate 11,000 stranded seafarers through the Strait of Hormuz.

The International Maritime Organisation announced the plan.

Its secretary-general, Arsenio Dominguez, said in a statement that "this large-scale operation will be carried out in close cooperation with Iran, Oman, all other coastal states in the region, the United States and the maritime industry."

"We have secured the necessary safety guarantees and have thoroughly verified the conditions for safe navigation to support these operations," he said.

The IMO's announcement included instructions from Oman on how ships could travel through the strait, the narrow mouth of the Persian Gulf through which a fifth of all oil and natural gas traded before the war.

But the uneasy ceasefire already has been tested by Iran saying it closed the strait again over fighting between Israel and the Iranian-backed militia Hezbollah in Lebanon.