The new head of Iran’s top security body warned Sunday that Tehran will see any country’s support for new U.S. economic measures against the Islamic Republic as an “act of war,” while Iran’s president defended a memorandum of understanding with the United States as the best way out of the stalled conflict.

Treasury Secretary Scott Bessent on Monday is expected to announce the new measures after the U.S. vowed to impose an “unprecedented” level of economic warfare and isolation on a country that has lived for decades under sanctions. Also Monday, Pakistan’s army chief is expected to visit Iran as mediators try to revive talks.

Meanwhile, attacks calmed on the Strait of Hormuz but posturing did not, as a recently created Iranian authority listed dozens of vessels it said will face restrictions on future transits.

Here’s a look at the latest developments in the Iran war and the wider Middle East on Sunday. Full coverage can be found here.

The hard-line leader of Iran’s Supreme National Security Council, Mohsen Rezaei, issued his latest warning on X, with the comments quickly shared by Iranian state media.

It came a day after Rezaei’s most extensive public comments since being named to the post this month.

“If (Trump) wants to do something, we will retaliate in a seismic manner,” he had told the state broadcaster in an interview that aired late Saturday. He said Iran would target other oil-shipping routes from the Persian Gulf — alternatives to the Strait of Hormuz.

Rezaei, a former Revolutionary Guard commander and military adviser to Supreme Leader Ayatollah Mojtaba Khamenei, was part of senior appointments widely seen as hardening Tehran’s political and military stance.

Iranian President Masoud Pezeshkian earlier Sunday said the memorandum of understanding signed in mid-June was the best way to move beyond a situation of “neither war nor peace,” adding that Tehran can’t attract investment nearly six months after the war began.

“There is not a single provision in this agreement that amounts to capitulation,” Pezeshkian said in a speech published by state-run IRNA. “The supreme leader sets the policies, and we will follow that path.”

The interim deal opened a 60-day period for talks aimed at ending the war and reaching an accord on Iran’s nuclear program. That period ended last week with no signs of compromise or extension.

There were no confirmed attacks in the Strait of Hormuz over the past 48 hours, a multinational coalition overseen by the U.S. Navy said Sunday, with shipping traffic still at reduced levels. The U.S. military said its blockade of Iranian ports had redirected 70 commercial ships and disabled three as of Sunday.

Iran’s recently created Persian Gulf Strait Authority, sanctioned by the U.S., published a list of dozens of ships it said had violated arrangements for transiting the strait and would face future restrictions like fines or seizures. The strait had been considered an international waterway before the U.S. and Israel attacked Iran on Feb. 28.

Iran and Oman, on the strait’s other side, are now discussing management of it, which likely will include ships paying fees.

Pakistani Field Marshal Asim Munir will lead a delegation to Tehran on Monday, Iranian state television reported, citing Iran’s Foreign Ministry spokesperson, Esmail Baghaei.

Two regional officials said the visit was part of Islamabad’s efforts to de-escalate tensions between the United States and Iran and urge them to return to the negotiating table. The officials spoke on condition of anonymity because they were not authorized to discuss the matter publicly.

— By Munir Ahmed in Islamabad

The Iranian judiciary’s Mizan news agency reported the latest execution connected to nationwide protests early this year, saying Majid Adineh was arrested Jan. 9 in Mohammadshahr, west of Tehran.

The judiciary said forensic examinations indicated the handgun found on him had been fired on Jan. 8 and 9. Mizan said Adineh had joined the unrest following calls by groups opposed to Iran’s government and alleged that he had received training from groups outside the country. He was convicted under Iran’s law imposing harsher penalties for espionage and cooperation with hostile states.

Police arrested a 16-year-old boy from the Israeli settlement of Avigayil in the beating of a 61-year-old Palestinian, Saeed Muhammad Ibrahim Rabah, outside his home in the occupied West Bank, a year after he lost a leg after being shot by a settler.

Rabah told The Associated Press that the violence at his home in Khirbet al-Rakeez on Saturday was an effort to make families leave, but “we will remain, no matter what happens.”

Separately, the West Bank Health Ministry said a 14-year-old in the Askar refugee camp in Nablus was shot dead by Israeli forces, who did not immediately comment. The uncle of Islam Maher Ajouri, Nehad Ajouri, called the shooting indiscriminate.

And Israel’s military said it detained a suspect in a stabbing attack that wounded a 24-year-old Israeli man in the area of al-Auja in the West Bank. Israel’s emergency services said the man was in moderate condition.

Four-year-old Mohammed Taha died after an Israeli airstrike hit a central Gaza house on Sunday and wounded at least five others, according to the Al-Aqsa Martyrs Hospital, which received the casualties.

Israel’s military later said it struck and killed a Hamas commander in central Gaza. The hospital confirmed that the man named, Ismail Abu Ful, was killed.

An Israeli strike in southern Gaza wounded at least seven people, including three children, according to health officials at Nasser Hospital. The military did not immediately comment.

And Defense Minister Israel Katz in a statement said he instructed the military to “act immediately and forcefully” to prevent launches of balloons, kites or drones from Gaza toward nearby Israeli communities.

Before the Oct. 7, 2023, attack by Hamas-led militants on Israel — when 1,200 people were killed and 251 taken hostage — burning kites and balloons were sent from Gaza into southern Israel, causing fires and other damage.

Hamas in a statement Sunday accused Israel of “using children’s toys as a pretext” for attacks and further displacement of Gaza residents.