WASHINGTON, DOHA, ISTANBUL. U.S. President Donald Trump on Monday announced that Israel and Iran had agreed to a complete and total ceasefire, potentially ending a 12-day war that displaced millions in Tehran and raised fears of a broader conflict in the Middle East.

Trump made the announcement on his Truth Social platform, stating, “On the assumption that everything works as it should, which it will, I would like to congratulate both countries, Israel and Iran, on having the stamina, courage, and intelligence to end what should be called ‘THE 12 DAY WAR.’”

The ceasefire follows Israeli strikes on Iran’s nuclear facilities, joined by the United States over the weekend, amid concerns that Tehran was close to developing a nuclear weapon. Iran has consistently denied pursuing a nuclear weapons program, though Supreme Leader Ayatollah Ali Khamenei recently warned that, if the country wanted such weapons, world leaders “wouldn’t be able to stop us.”

Iranian Foreign Minister Abbas Araqchi said early Tuesday that if Israel halted its “illegal aggression” by 4 a.m. Tehran time (0030 GMT), Iran would not continue its retaliatory strikes. He added that “the final decision on the cessation of our military operations will be made later.”

No further Israeli attacks have been reported since that deadline.

A senior White House official said Trump brokered the deal in a call with Israeli Prime Minister Benjamin Netanyahu. Israel reportedly agreed to the ceasefire as long as Iran did not resume hostilities. Trump also indicated the ceasefire would begin in a phased approach, allowing ongoing missions to conclude.

Qatar’s Prime Minister Sheikh Mohammed bin Abdulrahman Al Thani played a key role in securing Iran’s agreement through a call with Iranian officials, a source familiar with the talks said.

U.S. Vice President JD Vance, Secretary of State Marco Rubio, and special envoy Steve Witkoff were also involved in direct and indirect communications with Iranian representatives, the White House said.

Neither Iran’s U.N. mission nor the Israeli embassy in Washington responded to Reuters’ requests for comment.

Earlier, three Israeli officials had indicated that Israel was prepared to wind down its military campaign and had relayed this position to Washington. Israeli media reported that Netanyahu instructed government ministers not to speak publicly about the developments.

The ceasefire announcement had immediate effects on financial markets. S&P 500 futures rose 0.4% late Monday, while U.S. crude futures dropped to their lowest level in more than a week during early Tuesday trading, easing fears of oil supply disruption.

Despite the ceasefire declaration, tensions remained high. The Israeli military issued two evacuation warnings to residents in Tehran late Monday and early Tuesday, while alarms were triggered in Israel’s southern Golan Heights due to fears of a hostile aircraft.

Iran’s limited missile attack on a U.S. base in Qatar preceded the ceasefire. Trump dismissed the strike as a “very weak response,” noting that Iran had given prior notice and no casualties occurred. Iran said the number of missiles it fired matched the number of bombs dropped by U.S. bombers on Iranian nuclear facilities over the weekend.

Qatar condemned the attack on Al Udeid Air Base, saying it violated the country’s sovereignty and airspace. A Qatari military official said 19 missiles were launched, 18 of which were intercepted. Trump claimed 14 were fired, 13 were intercepted, and one was allowed to land as it posed no threat.

Israeli airstrikes prior to the ceasefire targeted symbolic and strategic sites, including Evin Prison in Tehran, known for detaining political prisoners and dual nationals. Iranian state television aired surveillance footage showing the aftermath of the strike, while a human rights group expressed concern over the safety of detainees.

Israel also targeted infrastructure near the Fordo nuclear enrichment facility, one of the sites hit by U.S. bunker-buster bombs. The UN’s nuclear watchdog expects heavy damage at the site.

While Iran has signaled it does not seek a wider war, Israeli officials said they remain prepared for a longer, low-intensity conflict if necessary. The preferred outcome, according to an Israeli official, is that Iran agrees to the ceasefire and returns to negotiations with the U.S. over its nuclear program.

Trump had hinted at the possibility of regime change in Iran in a social media post over the weekend. The White House later clarified he was “simply raising a question.”

In Vienna, the International Atomic Energy Agency said it is awaiting further assessment of the damage to Iran’s nuclear sites. Meanwhile, the U.S. State Department confirmed the evacuation of around 250 American citizens and their families from Israel.

According to Human Rights Activists, a U.S.-based group tracking casualties, Israeli strikes have killed at least 974 people in Iran, including 387 civilians and 268 security personnel. In Israel, at least 24 people have been killed and over 1,000 wounded.

Russia, a close ally of Iran, condemned the U.S. and Israeli strikes. President Vladimir Putin called them “absolutely unprovoked aggression” during a meeting with Iran’s foreign minister in Moscow.

The situation remains fragile, as both sides test the boundaries of the ceasefire while the international community watches closely for signs of lasting peace or renewed violence.