Late on Sunday, Pakistan's Prime Minister Shehbaz Sharif announced that, following months of negotiations, the United States and Iran had agreed to a peace deal aimed at ending the war and preventing a wider regional conflict. The memorandum of understanding, due to be signed in Switzerland on Friday, has been welcomed by governments across the Middle East and beyond as a potential pathway out of a conflict that has killed thousands, disrupted global energy markets and raised fears of a broader regional war. Yet despite the optimism surrounding the announcement, significant questions remain. The full text of the agreement has not been published, key details are still unclear, and both Washington and Tehran have offered only limited information about what has actually been agreed.
So what do we know so far, and what remains uncertain? The Strait of Hormuz The most economically significant element of the agreement concerns the Strait of Hormuz , the strategic waterway through which roughly a fifth of the world's oil supply passes.
Iran closed the strait after the joint US-Israeli attack on 28 February that triggered the war.
In announcing the deal, US President Donald Trump declared on Truth Social that he would remove the US naval blockade and authorise the reopening of the strait.
"Ships of the World, start your engines. Let the oil flow!" he wrote. Trump later clarified that the reopening would take place only after the agreement is formally signed on Friday.
However, exactly how the strait will operate remains unclear.
Notably, Sharif made no mention of the Strait of Hormuz when announcing the agreement.
Details published by Iran's Mehr news agency state that the waterway would reopen within 30 days under "Iranian arrangements", while the US naval blockade would also be lifted within 30 days.
Iran's Fars news agency reported that future shipping arrangements would be coordinated with Oman.
Washington has long opposed any Iranian-controlled tolling system or restrictions on navigation , while European powers have stressed that freedom of navigation through the strait must remain unrestricted.
The uncertainty has not prevented markets from reacting positively. Oil prices fell sharply following the announcement, reaching their lowest levels since early March.
However, restoring Gulf energy production and shipping routes could take months, while questions remain over whether insurers and shipping companies will consider the route safe enough to resume normal operations. Lebanon One of the most politically sensitive questions surrounding the agreement is whether it includes a binding end to Israel's war on Lebanon - Iranian officials have been unequivocal on the issue.
Deputy Foreign Minister Kazem Gharibabadi said a "permanent and immediate end to the war has been declared on all fronts, including Lebanon".
Sharif echoed that position, stating that both sides had agreed to the "immediate and permanent termination of military operations on all fronts, including in Lebanon".
Trump, however, made no mention of Lebanon in his initial announcements, focusing almost entirely on the Strait of Hormuz and Iran's nuclear programme.
The issue remains particularly contentious because Israel was not directly involved in the negotiations and has already rejected the agreement's Lebanon provisions.
Israeli Defence Minister Israel Katz said Israeli forces would remain in so-called "security zones" in Lebanon, Syria and Gaza "without any time limit".
Prime Minister Benjamin Netanyahu has reportedly informed Trump that Israel does not consider itself bound by the Lebanon-related aspects of the agreement and will not withdraw from occupied areas of southern Lebanon.
Israel's military campaign in Lebanon became a major obstacle during negotiations between Washington and Tehran. Iranian officials repeatedly insisted that any agreement must include an end to Israeli military operations in Lebanon.
Earlier attempts to finalise the agreement were also disrupted by Israeli actions. According to Trump, an Israeli strike on Beirut's southern suburbs delayed the signing process by several hours.
The issue has also exposed growing tensions between Trump and Netanyahu. Following the latest strike, Trump described Netanyahu as "a very difficult guy" and suggested Israel should be grateful for US efforts to secure the agreement.
"He should be very thankful to us for doing this," Trump told the New York Times . "If Iran had a nuclear weapon, Israel wouldn't be around for two hours."
Whether Israel ultimately accepts or undermines the Lebanon component of the agreement may prove one of the most important tests of its durability. Iran's nuclear programme The future of Iran's nuclear programme remains one of the least resolved aspects of the agreement.
Neither Trump's announcement nor Sharif's initial statement contained detailed provisions on nuclear issues, despite the programme being the central justification given by Washington for launching military action.
According to details published by Mehr , the two sides will enter a further 60-day negotiating period after Friday's signing to reach a broader agreement on nuclear matters.
The memorandum reportedly includes a commitment by Iran not to produce nuclear weapons, in line with its obligations under the Nuclear Non-Proliferation Treaty.
Trump has indicated that the US expects Iran to significantly reduce its stockpile of highly enriched uranium. In the interview with the New York Times , he suggested Tehran would dilute uranium currently enriched to near weapons-grade levels.
Senior Pakistani officials have also indicated that nuclear negotiations will continue during the next phase of talks.
However, major questions remain unanswered, including the future of Iran's estimated 400kg stockpile of highly enriched uranium and the extent to which Tehran will accept additional restrictions.
Trump has warned that military action could resume if negotiations fail.
European powers have similarly linked future sanctions relief to "clear, verifiable steps" by Iran on its nuclear programme.
Iran, meanwhile, continues to insist that its nuclear programme is peaceful and has not publicly committed to surrendering its existing enriched uranium stockpile. Sanctions relief Although sanctions relief was not highlighted in Trump's or Sharif's announcements, Iranian media reports suggest it could form a major component of the agreement.
According to Mehr , the deal includes the suspension of sanctions on Iranian oil exports , petrochemical products and related industries.
The report also states that $24 billion in frozen Iranian assets could be released during the 60-day negotiation period, with half of that amount reportedly released immediately to facilitate talks. Mehr further reported that the United States and its allies would present Iran with a reconstruction package worth at least $300 billion.
None of these provisions have yet been publicly confirmed by Washington.
However, sanctions relief was referenced indirectly by the UK, France, Germany and Italy, which stated they would be prepared to lift sanctions if Iran takes verifiable steps to limit its nuclear activities.
Trump has also suggested that sanctions relief could remain conditional. In his interview with the New York Times , he indicated that broader sanctions relief could be withheld if Iran continued its crackdown on domestic protests. What remains unknown? Despite the agreement's announcement, several major issues remain unresolved.
According to Iranian reports, the memorandum includes commitments on non-interference in Iranian domestic affairs, restrictions on future US military deployments around Iran and the creation of a supervisory mechanism to oversee implementation.
The agreement is also expected to require approval by the UN Security Council.
Yet some of the issues most frequently cited as causes of the war appear to have been left out entirely.
Neither Iran's ballistic missile programme nor its support for regional allies such as Hezbollah appear to be included in the initial agreement, according to reports published by Mehr .
Whether those issues emerge during the next 60 days of negotiations could prove crucial to the agreement's long-term survival.