Editor's note: As the United States launched attacks on three nuclear sites in Iran over the weekend, this page examines the escalating Middle East crisis despite renewed diplomatic efforts by relevant parties, and the potential economic ripple effects that threaten regional stability and global markets.

Strongly condemning the United States' "brutal military aggression" against Iran's peaceful nuclear facilities on Sunday, Iran emphasized its right and will to defend itself and struck Israel with new missiles.

The US is joining Israel in its attacks on Iran "to its own detriment", Iranian Supreme Leader Ayatollah Ali Khamenei has warned.

The US strikes on nuclear energy facilities at Natanz, Fordow and Isfahan escalated the conflict and added to damage inflicted by Israeli airstrikes since its surprise attacks on June 13, raising alarm over violations of international law and consequential contamination.

In a Sunday statement on the X platform, Iran's Foreign Ministry said: "The world must not forget that it was the United States that, in the midst of a diplomatic process, betrayed diplomacy by supporting the genocidal and law-breaking Israeli regime to impose a war of aggression on the Iranian nation.

"The warmongering and lawless regime of the United States of America is held fully responsible for the dangerous consequences and far-reaching implications of this egregious act of aggression and heinous crime," the statement said, adding that Iran has "resolved to defend Iran's territory, sovereignty, security and people".

It also called out the United Nations, the UN Security Council, the International Atomic Energy Agency, and other relevant international bodies "to take urgent and decisive action in response to this appalling breach of international law".

The Atomic Energy Organization of Iran has condemned the US attacks on Iran's nuclear sites, which it said contradicts international law, especially the Nuclear Non-Proliferation Treaty, according to its statement.

Morteza Heydari, a spokesman for Qom Provincial Crisis Management Headquarters, was quoted by Iran's Tasnim News Agency as saying: "Hours ago, after Qom's air defenses were activated and hostile targets were identified, part of the Fordow nuclear site was attacked by enemy airstrikes."

Iran had been expecting attacks on Fordow for several nights, and the facility had been evacuated before the airstrikes occurred, and did not suffer irreversible damage, according to an adviser to Iran's Parliament speaker.

In a phone call with his Egyptian counterpart Abdel Fattah El-Sisi on Sunday, Iranian President Masoud Pezeshkian said his country would give a firm and decisive response to the "aggression by the US-backed Israeli regime", noting Israel has been trying to drag the US into the conflict.

The Islamic Revolutionary Guard Corps said, for the first time, it launched multiwarhead Kheibarshekan (castle buster) ballistic missiles in its retaliatory strikes against Israel, Tasnim News Agency reported on Sunday.

Israeli public broadcaster Kan, citing an anonymous Israeli official, said Israel was "in full coordination with the US" during its attacks on Iran.

Inside Israel, sirens sounded across central and northern parts as Iran launched ballistic missile strikes, its first since June 13 after the US attacks, against Israeli targets, in addition to drone and other missile retaliations. The Times of Israel reported at least two dozen people were wounded.

The Israel Defense Forces, early on Sunday, decided to shift all areas of the country from Partial and Limited Activity to Essential Activity, thus prohibiting educational activities and gatherings, except for essential sectors. The IDF also launched more airstrikes against the military and related targets inside Iran.