US President Donald Trump speaks to reporters before leaving the White House for Miami on March 20, 2026 in Washington, DC.
Celal Gunes | Anadolu | Getty Images
As the Middle East war enters its fourth week and the end of the Trump administration’s 48-hour ultimatum approaches, Iran has expanded its warnings to target buyers of U.S. debt, the latest salvo in an escalating exchange of threats.
Iranian Parliament Speaker Mohammad Berger Ghalibaf said in a social media post on Sunday that U.S.-linked financial institutions holding U.S. debt would also be targeted, along with military bases.
“U.S. bonds are steeped in Iranian blood. If you buy them, you are buying a strike against our headquarters and our assets,” Ghalibaf said. “Along with military bases, financial institutions that fund the US military budget are also legitimate targets,” he added in the post.
The escalation of warnings came after US President Donald Trump issued a 48-hour ultimatum to Tehran on Saturday to reopen the Strait of Hormuz, a key artery for global energy transport, or face strikes on power plants. The deadline is scheduled to end Monday night in Washington.
Israeli Prime Minister Benjamin Netanyahu vowed to back up the U.S. threat, saying, “Whatever we do, we will do it as secretly and cooperatively as possible.”
Prime Minister Benjamin Netanyahu spoke on Sunday at the site of an Iranian missile attack in the southern city of Arad, calling on world leaders, including European countries, to join the war. “They have the ability to reach deep into Europe… They have everyone in their sights.”
Iran reacted by threatening to completely shut down the waterway and attack energy infrastructure and desalination facilities in the Gulf if the U.S. complied with the ultimatum.
Ghalibaf warned on Sunday that a U.S. or Israeli attack on Iranian power plants would “immediately” trigger retaliatory attacks on energy and oil infrastructure across the region, causing “irreparable” damage.
“Critical infrastructure, energy and oil infrastructure across the region will be considered legitimate targets and will be irreversibly destroyed. Oil prices will rise for a long time,” Ghalibaf said on the X program.
I can’t see the exit light
Markets had expected the development to lead to a so-called “TACO trade,” citing Trump’s history of refusing threats to calm the situation, but the president’s latest ultimatum appears to be holding up, said Aaron Costello, head of Asia at Cambridge Associates.
“The longer this goes on, the bigger the impact,” Costello told CNBC’s “Squawk Box Asia” on Monday, adding that the worst-case scenario would be for the conflict to last more than a month, leading to critical shortages of primary goods and energy supplies.
“Even if it subsides in a week or two, it will take some time for supplies to rebalance and come back online,” Costello added.

Military clashes continued to escalate over the weekend, with reports suggesting Israel was experiencing heavy missile activity, and multiple warnings were issued for people to evacuate to Jerusalem and central Israel. According to Al Jazeera, at least eight locations, mainly in central Israel, were damaged by falling objects and explosives.
The Israeli military announced on Monday that it had launched a major attack targeting Iranian infrastructure in Tehran, with reports of explosions in several locations in the capital early Monday.
Iran continues to fire missiles and drones at Israel and Gulf states that host U.S. assets. Kuwait and the United Arab Emirates said on Monday that air raid sirens were sounded in Bahrain and that their air defenses had intercepted more hostile missile and drone attacks from Iran.
Separately, Saudi Arabia’s Ministry of Defense announced that it had detected two ballistic missiles fired towards the Riyadh region. A ministry spokesperson said one plane was captured and the other crashed into no-man’s land.
Israeli and US airstrikes have killed at least 1,500 people in Iran so far, according to Iran’s Health Ministry. However, US-based human rights group HRANA, which tracks human rights violations in Iran, recorded 3,320 deaths, including 1,406 civilians and 1,167 military personnel.
Iran has effectively shut down much of the Strait of Hormuz to shipping traffic since the United States and Israel launched attacks on the country on February 28. Oil prices have soared in recent weeks amid concerns about a worsening oil supply shock due to the escalating conflict in the Middle East, raising concerns about inflation and weighing on growth.
Oil prices soared in volatile trading on Monday. Brent crude oil reversed an earlier decline and rose 0.44% to $112.68 per barrel as of 10:57 p.m. ET. US West Texas Intermediate rose 0.78% to $99 per barrel.
Nate Swanson, director of the Atlantic Council’s Iran Strategy Project, said Tehran would rather fight a long war with the United States than face repeated conflicts with Israel.
“They don’t have to fight a symmetrical war. They just have to survive,” Swanson said of Iran on CNBC’s Squawkbox Asia on Monday, but said the United States would need to annihilate the regime to fully achieve its objectives.
“Survival is victory for Iran,” he said. “It is enough for them to occasionally attack tankers passing through the strait. Even if they are not completely mined, they are effectively bottlenecked.”
