TIMELINE: Key moments in the US-Iran relations from 1953 to 2025, before Trump announced strikes

Tehran, however, has repeatedly said it will not talk to the Trump government until Israeli attacks end.

Talks between Iran and the U.S. collapsed when Israel launched what it called Operation Rising Lion against Iran's nuclear facilities and ballistic capabilities on June 12. On Saturday (June 21), Trump said on the U.S. had struck three Iranian nuclear sites, joining Israel's air campaign.

Following is a chronology of major events in relations between the Iran and the United States:

1953 - The CIA helps orchestrate overthrow of Iran’s popular Prime Minister Mohammed Mossadegh, restoring to power Shah Mohammed Reza Pahlavi.

1957 - The U.S. and Iran sign an agreement on civil nuclear cooperation.

1967 - The U.S. provides Iran with a nuclear reactor along with weapons-grade 93 percent enriched uranium fuel.

1968 - Iran signs the Nuclear Non-Proliferation Treaty which permits it to have a civil nuclear program in return for a commitment not to acquire nuclear weapons.

1979 - Iran’s Islamic Revolution forces U.S.-backed shah to flee, Ayatollah Ruhollah Khomeini returns from exile and becomes supreme religious guide. Fundamentalist students seize the U.S. Embassy in Tehran and hold staff hostage.

1980 - The U.S. cuts diplomatic ties with Iran, seizes Iranian assets and bans most trade with it; hostage rescue mission ordered by President Jimmy Carter fails.

1981 - Iran releases 52 U.S. hostages minutes after Carter steps down and Ronald Reagan is inaugurated as U.S. president.

1984 - U.S. lists Iran as a state sponsor of terrorism.

1986 - Reagan reveals secret arms deal with Tehran in violation of U.S. arms embargo.

1988 - U.S. warship Vincennes mistakenly shoots down Iranian passenger plane over the Gulf, killing all 290 aboard.

2002 - President George W. Bush declares Iran, Iraq, North Korea an "axis of evil." U.S. officials accuse Tehran of operating secret nuclear weapons program.

2009 - Britain, France and the United States announce that Iran is building a secret uranium-enrichment site at Fordow.

Iran says in May it will increase enriched uranium production, bucking its commitments under the nuclear accord.

Saudi Arabia’s state-run oil company is attacked in September by drones and missiles believed to be from Iran; Tehran denies involvement.

2020 - Iran vows harsh revenge after a U.S. air strike in Baghdad kills special forces commander Qassem Soleimani, architect of Iran's military influence in the Middle East.

2021 - U.S. and Iranian officials hold six rounds of indirect nuclear talks in Vienna between April and June. A new round begins on Nov. 29 after a five-month hiatus triggered by the election of Iran's hardline president Ebrahim Raisi.

2022 - Indirect talks between Tehran and Washington stall in September, leading both sides to sketch out steps that could free some detained U.S. citizens and unfreeze some Iranian assets abroad.

2023 - In August, Iran and the United States agree a prisoner swap and the unfreezing of $6 billion of Iranian assets in South Korea.

2025 - Ahead of his meeting with Israeli Prime Minister Benjamin Netanyahu, Trump signs presidential memorandum reimposing Washington's tough policy on Iran that was practiced throughout his first term. Iran's Supreme Leader Ayatollah Ali Khamenei rejects U.S. President Donald Trump's demand for unconditional surrender. On June 21, Donald Trump said the U.S. stuck three Iranian nuclear sites, joining Israel's air campaign that began on June 13.