US President Donald Trump was reported by Reuters to have signed the document, citing an unnamed White House official, while Iran’s foreign ministry spokesperson Esmaeil Baghaei told Iranian state media that Iran’s President Masoud Pezeshkian had also signed.

All parties in the regional conflict are committed by the memorandum to refrain from attacks or threats. Israel has the right to retaliate should Hezbollah attack.

If the deal holds, the contested Strait of Hormuz would reopen for transit by commercial vessels within 30 days. It remains unclear whether tolls will become a feature of the passage at a later time, with Iran claiming it will charge fees after 60 days, but it appears there will be a toll-free period of travel for vessels.

Both sides have 60 days to reach a final deal that would then be endorsed by a binding UN Security Council resolution.

The White House has not published the terms of the MoU. An administration official read out the terms of the agreement on a briefing call to journalists.

The memorandum to end the fighting is the first step of what is expected to be a lengthy process of negotiations on details ranging from sanctions and frozen Iranian assets, to enriched nuclear material -- the US claimed Iran has conceded to eliminating its enriched nuclear stockpile -- to conditions for passage through the Strait of Hormuz. One aspect of the negotiations that, for now, is settled is the US Treasury’s granting of a waiver on sanctions against Iranian crude oil exports.

There were hints of a move to allow Iranian oil back into the open market in vessel traffic patterns and military threat designations around the Strait of Hormuz in the days after the US and Iran indicated that the beginnings of a peace deal had been reached in their three-and-a-half-month war.

On 17 June, maritime tracking firms reported the unrestricted passage of Iranian oil tankers from ports and through waters that the US had, until that point, blockaded for several weeks.

Late on 16 June, the US-led, Bahrain-headquartered naval coalition, the Joint Maritime Information Center (JMIC) lowered its threat designation for the Middle East Gulf, Strait of Hormuz and Gulf of Oman. The 47-nation naval coalition led by US forces lowered the threat level to ’substantial’ from ’severe’, still warning of "residual kinetic risk and potential for rapid escalation" for the Strait of Hormuz and the waters on either side.

On 14 June, the JMIC had warned vessel owners, operators and mariners on board vessels on either side of the contested Strait of Hormuz to avoid transit in and out of Iranian ports, with the threat level set at ’severe’. A day after US and Israeli aerial strikes began in Iran, on 1 March, the JMIC had set the regional threat level to its highest, ’critical’, reporting at the time that "the maritime environment has quickly transitioned from elevated tension to active kinetic exposure".

As of its lowered threat designation on 16 June, the JMIC said "vessels transiting the area [through the Strait of Hormuz] are advised to navigate with extreme caution", citing continued satellite positioning interference and the threat of mines.

Blockade enforcement of Iranian ports by US naval forces in the Gulf of Oman, cited as "ongoing" and a justification for a severe threat designation by JMIC through 14 June, had been declared "active" in the 16 June JMIC report.

"Navigation interference persists. Mine-risk reporting remains relevant within and adjacent to the TSS [traffic security scheme]. An attack is a strong possibility, but overall risk has decreased following the announced agreement on the US–Iran Memorandum of Understanding. Thepotential for miscalculation endures given continued Iranian activity in the area," the JMIC said.

On 15 June, the JMIC said "mariners should expect increased naval presence, enhanced force protection postures, potential VHF hailing, and congestion near anchorage areas" and that masters should consider safety of crews and "not transiting to/from Iranian ports until direction is given".

"Blockade of Iran ports remains in effect pending execution of a US-Iran cease fire agreement," the 15 June assessment said. "Do not attempt to cross until explicit direction is given."

"The blockade is being enforced strictly and rapidly. While the maritime warning zone is not intended to impede neutral or merchant shipping, vessels should make their intentions clear, particularly demonstrating that they are not intending to visit/depart from an Iranian port. If vessels do not comply with blockading forces immediately upon being contacted, they risk being fired upon."

In the week leading up to the announcements of a more complete ceasefire under the memorandum of understanding, the US ’disabled’ three tankers, all with links to India and transport of Iranian crude, in as many days, killing three seafarers in one attack.

BIMCO says Hormuz transits ’risky’, says international coordinating body to be convened soon to facilitate transits