US-Israel Attack On Iran: A Timeline Of Nuclear Negotiations Before The Killing of Khamenei

Iran’s Supreme Leader Ali Khamenei has been confirmed killed following joint military strikes by the United States and Israel. Iran responded with missile and air strikes in Israel, Bahrain, Saudi Arabia, Qatar, the United Arab Emirates and Iraq.

The escalation comes against the backdrop of negotiations over Iran’s nuclear enrichment programme. The death of the Supreme Leader has commenced 40 days of national mourning in Iran. 

On February 26, Oman, which has been serving as a key mediator between Washington and Tehran, said the negotiators were “demonstrating unprecedented openness to new and creative ideas and solutions.”

The third round of negotiations between Iran and the US in Switzerland concluded with Omani Foreign Minister Sayyid Badr Albusaidi saying in a social media post that “significant progress” had been made.

However, US President Donald Trump stated that he was not happy with the negotiations and that military intervention in Iran remained an option.

“I say no enrichment,” Trump said. “Not 20 per cent, 30 per cent, they always want 20 per cent, 30 per cent, they want it for civilian, you know, for civil. I think it’s uncivil.”

The negotiations between the United States and Iran, which restarted last month, constitute of differing positions: the US had insisted that Tehran dismantle its nuclear infrastructure entirely, limit its ballistic missile arsenal and cease support for regional allies as part of any deal, while Iran had shown some willingness to discuss limits on uranium enrichment for civilian use but continued to treat its missile programme and support for proxy groups as off-limits in the talks.

On February 28, the attack began with strikes on Tehran. Along with Khamenei, state media reported that Khamenei's daughter, son-in-law and grandchild were also killed. As questions of regime change in Iran linger, here’s a look back at how the events unfolded since last year’s June attack on Iran.

June 13, 2025: 

After returning to office in 2025, Trump reinstated his “maximum pressure” campaign against Tehran while simultaneously reopening negotiations over Iran’s nuclear programme. On June 12, the International Atomic Energy Agency (IAEA) declared that Iran was in breach of its non-proliferation obligations for the first time in two decades. In response, Tehran announced plans to open a previously undisclosed uranium enrichment facility.

A day later, Israel carried out a unilateral military strike on Iran, targeting nuclear facilities and missile production sites. Iran’s Foreign Minister Abbas Araghchi described the assault as “an act of war,” after which Iran retaliated with waves of drones and dozens of ballistic missiles.

June 22: 

In the Operation Midnight Hammer, the United States strike targeted three enrichment sites in Iran: Fordo, Natanz and Isfahan. The attack “did, in fact, obliterate Iran’s nuclear facilities,” Karoline Leavitt, the White House spokesperson said. Iranian officials stated that their programme was set back but not destroyed.  Iran responded with strikes on a US military base in Qatar.

The strikes were launched as Israel and Iran attacks were ongoing, killing scores on both sides.

June 24:

The US announced a ceasefire between what came to be known as the Twelve-Day War. Israeli Prime Minister Benjamin Netanyahu had declared victory, mentioning that Israeli attacks had sent Tehran’s nuclear programme “to oblivion”. Khamenei said in a social media post that those who know the Iranian people and their history know that the “Iranian nation isn’t a nation that surrenders.”

July 2: 

Iran’s parliament voted on June 25, 2025 to suspend cooperation with the IAEA, halting ties with the UN nuclear watchdog until the security of its nuclear facilities can be guaranteed. On July 2, Iran’s President Masoud Pezeshkian signed the motion into a law.

As a result,  IAEA inspectors were not permitted anymore to visit the nuclear sites without prior approval from the Supreme National Security Council, making it difficult to assess the intensity of damage done by the US strikes. It also shrouded international visibility for the location of any highly enriched uranium stockpile.

July 22: 

Araghchi has stated that Tehran will not abandon its uranium enrichment programme, despite the damage. “It is now stopped because, yes, damages are serious and severe, but obviously, we cannot give up our enrichment because it is an achievement of our own scientists, and now, more than that, it is a question of national pride,” Araghchi said.

He noted that Iran remains “open to talks” with the United States, though any engagement would not be direct discussions “for the time being”.

August 28:

The E3, namely France, Germany and the United Kingdom, triggered a mechanism to reimpose sanctions on Iran after multiple meetings failed to produce an agreement on the Iranian nuclear programme, opening the way for previously lifted United Nations sanctions to automatically return. 

The E3 accused Iran of violating provisions of the 2015 nuclear pact in which Tehran had agreed to limit its nuclear programme in exchange for international sanctions to be lifted.

Araghchi said that renewing the sanctions would have consequences, and dismissed the E3’s decision as “unjustified, illegal and lacking any legal basis.”

November 1:

Oman, which hosted several rounds of US-Iran nuclear negotiations that were disrupted by the Israel-Iran conflict in June, urged both countries to return to the negotiating table.

“We want to return to the negotiations between Iran (and) the United States,” Omani Foreign Minister Badr Albusaidi said.

However, he added, “just three days before the sixth and possibly decisive round of talks, Israel unleashed its bombs and missiles in an illegal and deadly act of sabotage,” referring to Israel’s operation intended to halt Iran’s nuclear weapons development.

November 7:

Iran reached out to Washington to ask whether US sanctions could be lifted, Trump said. 

“Iran has been asking if the sanctions could be lifted. Iran has got very heavy US sanctions, and it makes it really hard for them to do what they'd like to be able to do. And I'm open to hearing that, and we'll see what happens, but I would be open to it.”

However, Khamenei had stated that cooperation between the two countries would be impossible as long as Washington continued to support Israel, maintain military bases, and interfere in the Middle East.

November 19:

Trump said that after the US “obliterated” Iran’s nuclear capabilities, “They want to make a deal. They want to see if they can work out a deal with us, and we'll be doing that probably.”

However, Iran’s Foreign Ministry spokesman Esmail Baghaei denied the negotiation claims. “Talking to a side that does not believe in mutual respect and takes pride in military aggression against Iran has no logical justification.”

December 28: 

The protests in Iran began, triggered by a sharp collapse of the country’s currency amid soaring inflation, state mismanagement of essential services and worsening living conditions. The unrest initially started with shopkeepers in Tehran’s Grand Bazaar going on strike and closing their shops.

As more people joined, the protests quickly escalated into mass nationwide street demonstrations, with participants calling for the end of the Islamic Republic system.

By January 8, authorities imposed a near-total internet shutdown across Iran in response to the antigovernment unrest\. The blackout lasted for more than two weeks, severely restricting communication and access to information both domestically and internationally.

January 13:

US President Donald Trump on Tuesday called on Iranians to continue protesting and “remember the names of those abusing them,” assuring that help is on the way. Trump also stated that he had cancelled all meetings with Iranian officials until the “senseless killing” of protesters ceased.

As per reports, the demonstrations indicated that 2,000 Iranians had been killed, far exceeding the 600 deaths previously acknowledged by Iranian authorities.

February 17:

The US and Iran conducted high-level talks on Iran’s nuclear program in Geneva, mediated by Oman. According to Omani Foreign Minister Badr Albusaidi, the talks “concluded with good progress towards identifying common goals and relevant technical issues.”

Iranian Foreign Minister Abbas Araghchi added that “the path to an agreement has begun,” noting on Iranian state TV, adding that they were able to reach broad agreement on a “set of guiding principles”, based on which they will move forward.

Representing the US side, presidential envoy Steve Witkoff and Jared Kushner, attended the talks.A US official, speaking to Reuters on condition of anonymity, said: “Progress was made, ‌but there are ‌still a lot of details to discuss.”

February 26: 

The latest third round of nuclear talks took place with an atmosphere of constructive engagement, with the “a peace deal is within our reach.”

Albusaidi said that “efforts are continuing diligently and constructively, with the negotiators demonstrating unprecedented openness to new and creative ideas and solutions, and creating a supportive environment for progress and reaching a fair agreement with sustainable guarantees,” highlighting a breakthrough.

"If the ultimate objective is to ensure forever that Iran cannot have a nuclear bomb, I think we have cracked that problem through these negotiations by agreeing a very important breakthrough that has never been achieved any time before," Albusaidi told CBS News.

February 27: 

Trump said he was “not happy with the negotiation” with Iran over Tehran’s nuclear programme, stressing that he does not want any enrichment for Iran. “I am not happy with the negotiation,” Trump told reporters in Texas, adding that the Iranians “don’t want to quite go far enough. It’s too bad.”

February 28:

On Saturday, the US and Israel carried out a joint strike on Iran, resulting in the death of Khamenei, plunging Iran into uncertainty as Trump urged Iranians to rise against their government.

In a video posted on Truth Social, Trump said the operation aimed to “obliterate” Iran’s missile industry, claiming that Tehran had rejected “every opportunity to renounce their nuclear ambitions.” The strikes commenced in broad daylight on Saturday morning.

The attacks resulted in hundreds of civilian casualties, including students at a girls’ school struck by a drone.

 Iran condemned the assaults as unprovoked and illegal, responding with an unprecedented wave of retaliatory strikes targeting multiple countries hosting US military bases, including Bahrain and the United Arab Emirates.

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