WASHINGTON — US Iran sanctions are set for a major expansion Monday as Treasury Secretary Scott Bessent prepares to unveil a new economic campaign against Tehran that could reach beyond Iranian companies to foreign countries, banks and businesses that continue providing the regime with access to oil revenue and international commerce. Bessent has promised what he described as the toughest sanctions Washington has imposed on Iran, placing financial pressure at the center of President Donald Trump’s effort to break the current stalemate.
The announcement is expected later Monday, meaning the precise targets and legal authorities have not yet been made public. What is already clear is that the administration wants to make doing business with Iran substantially more costly for third parties, with China likely to face the most consequential decisions because of its role as the largest buyer of Iranian crude.
US Iran Sanctions Shift the Pressure to Economics
Bessent has described the administration’s approach as a combination of the existing pressure on Iranian shipping and a much more aggressive financial offensive. He said last week that Washington intended to use sanctions alongside the blockade as a coordinated strategy and urged governments around the world to decide whether maintaining economic ties with Tehran was worth the potential consequences.
That represents an escalation of a sanctions architecture that is already extensive. Treasury has repeatedly targeted Iranian oil networks, financial intermediaries, weapons procurement channels and entities accused of helping Tehran move money outside normal banking systems, but Monday’s expected announcement suggests the White House intends to put greater pressure on the foreign counterparties that allow those networks to function.
The distinction matters because Iran has spent years adapting to American restrictions. Tehran has relied on discounted oil sales, opaque shipping structures, intermediaries and non-dollar payment mechanisms to continue generating foreign currency even while much of the conventional Western financial system remains closed to it.
The administration is therefore confronting a familiar sanctions problem: penalizing Iran itself is easier than eliminating every external buyer willing to trade with it. To increase the economic effect, Washington must convince or pressure companies in third countries to decide that access to Iran is less valuable than access to the U.S. financial system and market.
China and Iranian Oil Move Into the Crosshairs
China is the biggest test of that strategy. It was the largest buyer of Iranian oil in 2025, when imports averaged roughly 1.4 million barrels per day, while Reuters estimates indicate Iranian exports to China fell to about 534,000 barrels per day in August from approximately 823,000 in July.
Much of that trade involves independent Chinese refiners rather than the country’s largest state-controlled oil companies. Washington has already sanctioned smaller Chinese refiners and warned financial institutions about transactions linked to Iranian crude, but expanding enforcement against larger counterparties would carry much greater economic and diplomatic risks.
Beijing signaled Monday that it will resist U.S. pressure. China’s Foreign Ministry said it would monitor the new measures and take steps necessary to protect Chinese interests, while continuing to argue that unilateral sanctions are not a viable way to resolve the conflict.
That sets up a test of American financial power as well as Iran policy. The dollar-based financial system gives Washington enormous leverage over banks and corporations that need access to U.S. markets, but using that leverage against major Chinese interests could turn an Iran sanctions campaign into another source of tension between the world’s two largest economies.
Hormuz Raises the Economic Stakes
The sanctions campaign is unfolding while commercial movement through the Strait of Hormuz remains severely disrupted. That waterway was one of the world’s most important energy corridors before the war, and continuing uncertainty over safe passage has kept a geopolitical premium embedded in crude prices.
American News Brief has previously examined how the Trump Iran war pushed oil higher as Hormuz traffic remained impaired. The same problem complicates the administration’s new sanctions strategy because successful restrictions on Iranian exports can increase pressure on Tehran while simultaneously tightening global energy supply.
Oil prices fell by more than $1 early Monday ahead of Bessent’s announcement, but that decline followed a strong two-week advance tied partly to constrained shipping through Hormuz. Brent was trading above $92 per barrel early Monday, leaving American consumers and businesses exposed to a conflict in which economic pressure can have consequences well beyond Iran.
For the Trump administration, the objective is to make those costs fall disproportionately on Tehran rather than on American motorists. That will depend in part on whether alternative supplies reach the market and whether Washington can restore more predictable commercial transit through the Gulf while tightening sanctions at the same time.
Sanctions Offer Leverage Without Another Major Strike
The attraction of economic pressure is straightforward. Financial sanctions can impose significant costs without immediately requiring another major military operation, giving Washington another instrument between diplomacy and direct force.
That approach is particularly relevant nearly six months into a conflict that has already produced major military and economic consequences. Bessent has argued that stronger economic measures can complement U.S. military pressure and eventually leave the Iranian government unable to finance its operations at the current level.
The record of sanctions, however, requires a distinction between inflicting economic damage and securing political concessions. Iran has endured severe restrictions before, and while those measures have constrained exports and access to foreign currency, Tehran has repeatedly demonstrated an ability to absorb substantial economic pain without immediately abandoning core security policies.
A credible pressure campaign therefore requires a defined objective and an identifiable path for sanctions relief if Iran changes course. Without an off-ramp, economic punishment can become a permanent condition rather than leverage that produces a specific strategic result.
Monday’s Announcement Will Define the Next Phase
Bessent’s press conference will answer several questions that remain unresolved early Monday. Markets will be watching for the number of entities designated, the sectors targeted, whether secondary sanctions are broadened and how aggressively Washington plans to pursue foreign banks, refiners, shipping companies and governments that maintain Iranian commercial ties.
The reaction from Beijing may be just as consequential as the list published by Treasury. If China continues buying significant quantities of Iranian crude and Washington chooses to impose meaningful penalties on the companies facilitating those purchases, US Iran sanctions could rapidly become a wider test of the administration’s willingness to use access to the American financial system as geopolitical leverage.
Iran, for its part, has dismissed the promised measures and warned that additional American pressure will not force capitulation. Tehran’s defiance does not mean the sanctions will be economically ineffective, but it does underline the difference between weakening an adversary’s finances and producing the political outcome Washington wants.
The administration has considerable economic tools available and good reason to target the financial networks that sustain hostile Iranian activity. The measure of success will not be the length of Monday’s sanctions list, however, but whether the campaign produces greater security, freer navigation through Hormuz and a clearer route toward ending rather than indefinitely financing the conflict.
