US–Iran MoU keeps mum on Tehran's nuclear capability. What are the other fault lines? Explained

The United States and Iran announced an interim deal to reopen the Strait of Hormuz, bringing an end to a conflict that claimed thousands of lives and paving the way for 60 days of negotiations over Iran’s nuclear programme.

According to a report by Bloomberg, officials from both countries are scheduled to meet in Switzerland on 19 June to formally sign the agreement, although the absence of a publicly released text suggests that several key issues remain unresolved and will be addressed in the next phase of talks.

But US President Donald Trump on Saturday had promised an agreement would be reached on Sunday — his 80th birthday — and he had pushed hard for it to go ahead.

“This Great Deal will bring Peace and Security to the whole Region,” Trump said in a post on social media. He said the strait would open on 19 June, after the agreement is signed and mines are removed from the waterway, Bloomberg reported.

Main unresolved or contested issues include:

Sanctions relief

A major sticking point in the negotiations is the issue of frozen assets and sanctions relief.

However, Reuters reported, citing a senior Iranian official, that the United States has agreed not to impose new sanctions on Iran while negotiations continue. The official also said Washington would temporarily waive oil-related sanctions and eventually lift all US and UN sanctions under a mutually agreed timeline if a final deal is reached.

In addition, the US is said to have agreed to release $25 billion in frozen Iranian assets through a combination of direct cash transfers, regional financial cooperation, and credit facilities.

Strait of Hormuz management

The memorandum of understanding is intended to restore civilian passage through the Strait of Hormuz, but disagreements remain over who will control the waterway. Iran insists on managing the strait under a sovereignty-based arrangement with Oman, including the ability to levy service fees, while the United States supports keeping it fully open without Iranian charges or interference.

Differences also persist over rules for military vessels, enforcement mechanisms, and implementation timelines. Iran has indicated it expects a post-deal management role, which contrasts with the US position.

Separately, the United States and Iran have announced an agreement aimed at ending the wider regional conflict and reopening the strategic strait, prompting relief after months of violence and economic disruption.

Few details were made public, but President Trump said Hormuz, a key conduit for global oil supplies that Iran has blockaded since the start of the war, would reopen.

"The Deal with the Islamic Republic of Iran is now complete," President Trump said on Sunday. "Ships of the World, start your engines. Let the oil flow!"

Lebanon ceasefire and regional proxies

The scope and enforcement of a Lebanon ceasefire tied to Hezbollah and Israel remain disputed. Iran favours arrangements that would preserve its influence through allied groups, while the United States and Israel are concerned about limiting proxy activity and preventing Hezbollah from rearming.

Israel has criticised the proposed framework, arguing that it does not adequately address its security concerns or ensure effective control and enforcement on the ground, particularly regarding compliance by armed groups in Lebanon.

Finance Minister Bezalel Smotrich also echoed the sentiment, calling the deal "bad for Israel", AFP reported.

Smotrich also called for a stronger campaign in Lebanon. "We will be judged in Lebanon. This is our war, our soldiers, and the immediate security of our northern residents," he said.

The claim that “the war started by Trump has killed thousands, mostly in Iran and Lebanon” is broadly consistent with available reporting, which estimates total deaths in the thousands across the wider conflict, particularly in Iran and Lebanon.

Nuclear programme

Most of the key nuclear issues have been pushed into the 60-day negotiation period.

In addition, the MOU does not fully resolve the fate of Iran’s near-bomb-grade uranium stockpile. These include the fate of Iran’s highly enriched uranium stockpile, such as whether it will be removed, diluted, or reprocessed under international verification.

Other major points are limits on enrichment and how long any moratorium would last, with reports suggesting discussions of 12–15 years or more, potentially followed by a phased resumption.

The status of nuclear facilities, inspection and verification mechanisms, and whether there will be permanent dismantlement or binding bans on weaponisation also remain unresolved.

But many other issues would still need to be addressed, including the duration of any suspension of Iran’s nuclear programme, whether key nuclear facilities would be dismantled, and the handling of uranium stockpiles enriched to 20% and 5%. Additional unresolved questions include the future of Iran’s advanced centrifuges, its research and development activities, and the scope and strictness of any inspections and verification regime, among others.

Trump said in a social media post on Saturday that the US would go in, get the material and “downblend and destroy it,” but gave no timetable. An Iranian official spoke only of Iran agreeing to “dilute” the stockpile on its own, but with no mechanism yet determined, Reuters reported.

"This deal is likely the best possible outcome to avert further conflict, but it is no better than what could have been achieved had the United States pursued diplomacy rather than war in the first place," said Victoria Taylor, a former deputy assistant secretary of state now at the Atlantic Council think tank.

It is still unclear whether the final agreement will improve upon the 2015 nuclear deal negotiated under President Barack Obama, which aimed to limit Iran’s nuclear programme in exchange for sanctions relief, but was later abandoned by Trump in 2018.

Ballistic missiles

Iran has opposed including major nuclear concessions in the initial memorandum of understanding. Ballistic missile development and related capabilities are also expected to be part of these broader negotiations.

A prominent U.S. demand before the war was that Iran limit the range of its ballistic missiles so that they could not reach Israel. Iran has always said its right to conventional weapons is non-negotiable and that it still has a large arsenal.

Trump chafes at comparison to Obama’s Iran nuclear deal

Trump strongly criticised former President Barack Obama’s 2015 nuclear agreement, arguing that it did not prevent Iran from progressing toward a nuclear weapon and effectively provided the Islamic Republic with billions of dollars in financial benefit. In 2018, Trump withdrew the United States from the deal, known as the Joint Comprehensive Plan of Action, which had also been signed by Britain, China, France, Germany, Russia, and the European Union.

But Trump’s deal is also expected to include some sanctions relief and economic incentives for Tehran as it meets certain benchmarks aimed at assuaging White House concerns, AP reported. Trump, in a new interview with The New York Times, pushed back on comparisons to the Obama-era nuclear deal.

“We negotiated from strength,” Trump said. “He was basically paying them off.”

Implementation, timelines, enforcement, and leverage

Key aspects of the agreement remain unclear, particularly the sequencing of steps, verification systems, enforcement measures in case either side violates the terms, and the overall framework of a potential long-term deal. Mutual mistrust between the parties is significant, with reports suggesting the existence of competing draft proposals and questions about internal approval processes within Iran.

The details of the agreement are still emerging after weeks of tense negotiations, which were accompanied by periodic warnings from Trump of renewed hostilities if a deal was not reached

Iran’s Mehr news agency reported that the United States would release $12 billion in frozen assets to Iran before formal negotiations begin. It also cited a 14-point memorandum of understanding stating that around $24 billion in Iranian funds would be unfrozen during the 60-day negotiation period following the signing of the MoU.

The announcement of the deal was greeted with international relief and hope for an enduring end to the conflict.

UN Secretary-General Antonio Guterres said it was a “critical step” toward resolving the war in the Middle East.

The United Kingdom, France, Germany and Italy said they were prepared to lift sanctions imposed on Iran and will work “with the US, Iran and regional partners to seize this moment, maintain momentum and achieve a long-term diplomatic settlement”.

(With inputs from agencies)