TEHRAN, April 18 -- Iran's military declared the Strait of Hormuz closed again today, its military command said, hours after reopening it and with more than a dozen commercial ships passing through the vital waterway.

The toing and froing over the strait cast doubt on US President Donald Trump's optimism the day before, that a peace deal to end the US-Israeli war with Iran was "very close".

Tehran had yesterday declared the strait, which usually carries a fifth of the world's oil and liquefied natural gas, open after a ceasefire was agreed in Lebanon to halt Israel's war with Hezbollah.

That prompted elation in global markets and sent oil prices plunging, but with Trump insisting that a US naval blockade of Iranian ports would continue...