Iran's Supreme Leader Ayatollah Ali Khamenei was killed, Iran's Fars News Agency reported on Sunday. The agency also later confirmed the deaths of Islamic Revolutionary Guard Corps (IRGC) Chief Commander Mohammad Pakpour and Defense Council Secretary Ali Shamkhani.

Citing sources, Fars News Agency also reported that four relatives of Khamenei, including his daughter, grandchild and son-in-law, were killed in the U.S.-Israeli strikes.

The Iranian government announced 40 days of public mourning. Iran's Revolutionary Guard vowed they would take revenge on Khamenei's killers.

The council of the Iranian president, head of the judiciary and one of the jurists of the Guardian council, a 12-member body that vets laws, will temporarily assume leadership duties in Iran, the Islamic Republic News Agency has reported.

Wang Jin, director of the Center for Strategic Studies at Northwest University, told CGTN that Iran would need to establish an expert committee to discuss and determine the next supreme leader following Khamenei's death. 

Under Iran's current system, the supreme leader is selected by the Assembly of Experts, but the body is now operating under wartime conditions, making it uncertain whether members can convene. Wang said this could create procedural delays in the succession process.

He added that it is possible Khamenei had already designated a successor in a private will. "According to precedent, Ayatollah Khomeini's succession followed his will, which was later endorsed by the Assembly of Experts," Wang said. "If Khamenei left a similar directive, it could guide the transition. But such documents are not public, so we do not know."

Wang emphasized that while the succession process could be complex, Iran's political institutions are likely to manage the transition without descending into chaos.

'Major combat operations'

The United States and Israel launched what they described as "major combat operations" against Iran on Saturday. Israel had earlier stated that all senior Iranian government officials were potential targets. Israeli Prime Minister Benjamin Netanyahu said the goal of the joint military action was to "topple Iran's ruling regime."

Trump said Iran was developing long-range missiles capable of threatening the United States, adding that the strikes aimed to dismantle Iran's missile industry and ensure that Tehran could not acquire nuclear weapons.

Iran's Red Crescent Society said 201 people were killed and 747 injured in the U.S.-Israeli attacks, according to the semi-official Tasnim news agency.

An expert suggests that Israel took the lead in the joint U.S.-Israeli strikes, with the United States acting as a supporting role.

CMG military commentator Wei Dongxu said Israel has established intelligence networks inside Iran and is capable of tracking senior military commanders and carrying out targeted "decapitation" strikes during the operation. This time, he said, Washington likely played a supporting role, such as conducting strikes on targets identified through Israeli intelligence.

Iran has responded with a wave of retaliatory strikes targeting Israel and U.S. assets across the region. Explosions were reported in Bahrain, Qatar, Kuwait, Jordan, the UAE and Saudi Arabia, among other locations. It has also closed the Strait of Hormuz, and Iran's Revolutionary Guard has told ships that passage through the strait is "not allowed."

In a statement issued at 1 a.m. local time Sunday, Iran's Islamic Revolutionary Guard Corps (IRGC) said four drones struck a U.S. ammunition transport vessel docked at Jebel Ali Port in the UAE, causing it to lose power and explode. The IRGC also claimed that a U.S. naval base in Kuwait was hit by four ballistic missiles and 12 drones, destroying infrastructure and causing heavy casualties among American personnel.

Additionally, Iran said it launched a missile strike against a U.S. MST-class combat support ship transporting fuel in the Indian Ocean. The IRGC's public relations department also announced that Prince Sultan Air Base in Saudi Arabia was precisely targeted by Iranian missiles and drones. It further claimed responsibility for a missile strike on the Harir military base in Iraq, which it said hosts U.S. special forces.

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Expert: Iran could target aircraft carrier USS Abraham Lincoln

Wei said given the current situation, Iran is likely to strike the United States and Israel without restraint.

He suggested that U.S. aircraft carrier USS Abraham Lincoln, deployed in the northern Arabian Sea, could become a potential target due to its proximity to Iran, approximately 600 to 700 kilometers away.

Wei added that Iran may deploy anti-ballistic missile systems, "suicide" drones and long-range reconnaissance drones in possible attacks.

Su Xiaohui, deputy director of the Department of American Studies at the China Institute of International Studies said military pressure alone is unlikely to force Iran to compromise or help the United States achieve its objectives.

"The launch of military operations has undermined the atmosphere for negotiations," Su said, warning that restarting talks would be extremely difficult, as Iran's trust in the United States has been severely eroded.

Iran's retaliation so far appears stronger than in the previous round of fighting. Su assessed that the conflict is likely to escalate further, with the scale of confrontation potentially surpassing last year's 12-day war.

At the same time, Su pointed out that both Washington and Tel Aviv face limitations. The United States is reluctant to become deeply entangled in another prolonged Middle East conflict, while regional countries are wary of a full-scale war that could further destabilize the region.

Another analyst has  questioned whether airstrikes alone could compel Iran to abandon its nuclear program.

"Without deploying ground forces inside Iran, it remains uncertain whether military pressure alone can force concessions," said Tang Zhichao, director of the Center for Middle East Development and Governance Studies at the Chinese Academy of Social Sciences. He warned that if the conflict becomes protracted, a more hardline government could emerge in Iran and retaliatory actions could lead to severe U.S. casualties, potentially turning the conflict into a major setback for Trump.

Trump says he has multiple off-ramps

On Saturday night, Netanyahu said in a televised address that operations against Iran "will continue as long as necessary to ensure that Iran no longer poses a threat." He said Israel would strike thousands of additional targets in the coming days, and warned that the Israeli military was prepared for any response from Iranian-backed forces in the region. He added that Israel and the United States were acting in full coordination.

Trump said he had left himself multiple off-ramps in the military campaign against Iran, saying he can stay engaged long-term and control the entire situation, or he can end this within two or three days.

Following the February 28 strikes by the United States and Israel, the FBI's counterterrorism and counterintelligence units went on high alert nationwide. A federal official said the bureau may increase both ground and cyber surveillance as part of heightened security measures. Police departments, including those in New York City, have also increased patrols amid concerns about potential domestic violence incidents.

The military action took place late at night (U.S. time), but as morning broke across the country, several American officials voiced criticism. Democratic Senator Tim Kaine condemned the operation as "dangerous, unnecessary and reckless," warning that it would put U.S. troops and diplomats in the Middle East at serious risk. He urged Congress to reconvene immediately to vote on the proposed War Powers Resolution, aimed at preventing the president from committing U.S. armed forces to war with Iran without congressional authorization.

International reactions

The escalating conflict has drawn widespread international concern, with many countries urging restraint and calling for a return to dialogue to prevent further destabilization in the Middle East.

UN Secretary-General Antonio Guterres, during an emergency meeting of the Security Council, expressed deep concern over the direct military confrontation between the U.S., Israel, and Iran. The UN chief called on the parties to immediately cease fire, emphasizing that further use of force would only lead to uncontrolled consequences for the entire world.

The International Atomic Energy Agency (IAEA) on Saturday urged all parties to exercise restraint and avoid actions that could pose nuclear safety risks. It said no radiological impact has been detected so far and that it will continue monitoring the situation.

Austrian Foreign Minister Beate Meinl-Reisinger said Iran's nuclear facilities have not been targeted at this stage, after she spoke with IAEA Director General Rafael Grossi.

The IAEA Board of Governors will hold a special meeting on Iran on March 2 local time.

The Chinese Foreign Ministry said it is highly concerned about the military strikes against Iran, emphasizing that Iran's sovereignty, security and territorial integrity should be respected. The ministry called for an immediate halt to military actions, de-escalation of tensions, and the resumption of dialogue to safeguard peace and stability in the Middle East.

Fu Cong, China's permanent representative to the UN, expressed his shock on Saturday over military strikes occurred at a time when the United States and Iran were engaged in diplomatic negotiations. He expressed China's deep concern over the situation and supported the UN Secretary-General's call for de-escalation and a return to diplomatic negotiations.