By Yasmine Ghania and Kanishka Singh
CAIRO/WASHINGTON, Aug 24 (Reuters) - The U.S. threatened Iran with what it called "the greatest financial offensive ever marshalled" as it prepared to roll out economic sanctions on Monday that target Iran's trade partners.
Iran in turn vowed to shut down all oil exports from the Gulf "if the economic war continues."
U.S. Treasury Secretary Scott Bessent will hold a press conference at 1 p.m. EDT (1700 GMT) on Monday amid promises to reveal even more severe measures on a country that has endured near-continuous economic sanctions since the Islamic Revolution of 1979.
"At dawn begins an economic D-Day — the single greatest financial offensive ever marshalled against an adversary," Bessent wrote in an opinion piece published in the Financial Times on Sunday.
The warring nations have not conducted military strikes against each other for weeks, but they also have not engaged in meaningful talks to end the six-month-old conflict.
Thousands of people have died, most of them in Iran and Lebanon, since the U.S. and Israel began strikes on February 28, degrading much of Iran's conventional military capacity and inflicting economic pain while killing Iranian Supreme Leader Ayatollah Ali Khamenei.
But Iran has preserved enough missile and drone capability to attack its Gulf neighbours and threaten oil tankers in the Strait of Hormuz, bringing shipping in the key waterway to a near standstill and pressuring world fuel prices. The exact state of Iran's nuclear program, which the Americans and Israelis aim to wipe out, remains unknown.
Without detailing specific measures, Bessent signalled the U.S. would target "fearful nations" that practice "appeasement" by engaging with Iran's economy and financial system.
"They would do well to consider the consequences of sustaining it," he wrote in the Financial Times.
Iran has been bracing for the sanctions for days, issuing a series of strongly worded statements hinting at a major military response.
Mohsen Rezaei, secretary of Iran's Supreme National Security Council, on Sunday suggested economic retaliation.
"If the economic war continues, not a single drop of oil will be exported, neither through the Strait of Hormuz nor from anywhere in the Persian Gulf," Rezaei wrote in a social media post. "Iran will regard any country’s participation in or support for America’s economic war against the Iranian people as an act of war."
Bessent previously urged China to cooperate with the U.S., noting China historically has received half of its oil imports from the Gulf region. A spokesperson for China's embassy in Washington responded with a statement that "sanctions and pressure do not help resolve the problem," while calling for diplomacy.
Iran's economy was already under pressure from international sanctions before the U.S. and Israeli attacks destroyed parts of its infrastructure.
Though Tehran remains outwardly defiant, Iranian officials have warned that further economic punishment could increase hardships, reignite unrest and further erode the Islamic Republic's legitimacy.
Iran entered the war with high inflation, a weakening currency, energy shortages, sanctions and deep structural weaknesses, and must now contend with damaged infrastructure, disrupted trade, lost production and the cost of rebuilding.
In the absence of official face-to-face talks between the U.S. and Iran, which were last conducted in June in Switzerland, other nations including Qatar, Pakistan and Turkey have attempted to promote diplomacy.
Iran saidPakistan's army chief, Asim Munir, will visit Tehran on Monday as part of efforts to restore peace and security in the region, but gave few details.
Pakistan has been mediating in the conflict and a Pakistani government source said Munir would touch on recent developments including the U.S. threat of new sanctions.
U.S.-Israeli strikes on Iran and Israeli attacks on Lebanon during the war have killed thousands and displaced millions. The U.S. reported 18 military personnel killed and more than 750 wounded.
(Reporting by Yasmine Ghania in Cairo and Kanishka Singh in Washington; Writing by Daniel Trotta; Editing by Chris Reese and Christian Schmollinger)
Facts Only
* The U.S. threatened Iran with a "greatest financial offensive ever marshalled."
* The U.S. prepared to roll out economic sanctions on Monday targeting Iran's trade partners.
* Iran vowed to shut down all oil exports from the Gulf if the economic war continues.
* U.S. Treasury Secretary Scott Bessent will hold a press conference at 1 p.m. EDT on Monday.
* The U.S. aims to target "fearful nations" practicing appeasement by engaging with Iran's economy.
* Iran suggested that if the economic war continues, no oil would be exported through the Strait of Hormuz or the Persian Gulf.
* Mohsen Rezaei suggested economic retaliation in response to the economic war.
* The U.S. and Israel began strikes on February 28, degrading Iran's military capacity.
* Iran has missile and drone capability to threaten oil tankers in the Strait of Hormuz.
* Iranian officials warned that further economic punishment could increase hardships and erode legitimacy.
Executive Summary
Full Take
The dynamic described involves a confrontation where stated economic threats are interwoven with underlying geopolitical and structural vulnerabilities. The exchange between the U.S. and Iran frames the conflict not just as a dispute over resource control, but as an existential contest of economic leverage, rooted in historical sanctions and ongoing instability. The threat to halt oil exports connects immediate energy security concerns directly to ideological conflict, suggesting that resource control functions as a primary mechanism for exerting geopolitical power, regardless of direct military engagement. Iran's response shifts the focus toward controlling its own strategic choke points (Strait of Hormuz) as leverage, reflecting a strategy of defensive escalation against perceived external pressures.
The persistence of this situation, despite the lack of overt military action and stalled talks, suggests a reliance on systemic pressure to manage conflict. The core pattern observed is the use of economic mechanisms—sanctions and resource denial—as primary tools for managing antagonism when direct confrontation is managed or avoided. This implies that control over global energy flows and financial systems remains central to the contest between these actors, with internal pressures (inflation, infrastructure damage) serving as compounding factors that increase the fragility of any negotiated outcome. The narrative structure relies on establishing a cycle where economic warfare precipitates demands for resource cessation, which in turn deepens internal instability, raising the stakes for all parties involved beyond immediate tactical gains to long-term legitimacy and survival.
Bridge questions: What are the specific thresholds Iran is signaling regarding its oil export control, and how do global energy markets currently respond to these threats? What alternative diplomatic frameworks exist that could decouple resource flows from ideological conflict management? How does the underlying damage to Iranian infrastructure influence the feasibility of any future economic reconciliation?
Sentinel — Human
The text reads like conventional, fact-based international reporting, characterized by attributed statements and contextual balancing typical of established news agencies.