Trump Vows Harsher Iran Sanctions: What Tools Remain?

US President Donald Trump has pledged to intensify economic pressure on Iran, following Treasury Secretary Scott Bessent's announcement that Washington would unveil measures against Tehran next week that have "never been seen" before.

This comes amid a long-running sanctions regime. The US, UN, and EU have imposed various restrictions since the late 1970s, targeting Iran's nuclear program, human rights record, and support for militant groups. Since February, Washington has added maritime, energy, and financial sanctions, alongside a naval blockade.

Data from the Treasury's Office of Foreign Assets Control (OFAC) shows over 1,000 individuals, vessels, and aircraft have been sanctioned since Trump's second term began. Recent actions have focused on Iran's shadow oil fleet, shipping insurers, weapons procurement networks, and digital exchanges, freezing an estimated $500 billion in Iran-linked cryptocurrency.

Experts suggest several additional avenues the administration could pursue:

Targeting Chinese 'Teapot' Refiners

Chinese independent refineries, known as "teapots," process a quarter of China's refining capacity and often operate on thin margins. They buy a significant share of Iran's shipped oil, making them vulnerable to secondary sanctions. While larger refiners have been deterred, these independents have minimal exposure to the US financial system, offering some immunity.

Pressuring Chinese Banks

OFAC has already sanctioned smaller Chinese and Hong Kong entities for processing Iranian oil payments. Treasury has warned two larger, unnamed Chinese banks about potential secondary sanctions but has stopped short of designating them. Hitting these banks could deter larger financial institutions, though it risks retaliation from Beijing. Officials are reportedly cautious, given upcoming talks between Trump and President Xi Jinping and concerns over China restricting critical mineral exports.

A 'Whack-a-Mole' Approach

Washington could continue targeting new entities facilitating Iran's oil-for-imports trade. However, analysts note this is a reactive strategy. Tehran often creates new front companies to replace sanctioned ones, meaning such measures may not fundamentally alter Iran's behavior. Experts suggest Bessent may be signaling a sharper focus on oil shippers, purchasers, and currency exchangers, with possible additional aviation sanctions.

Land Blockade

Some US and Israeli officials have floated a land blockade, which would require cooperation from Iran's neighbors, including Iraq, Turkey, Pakistan, and several Central Asian states. The US has varying ties with these nations, and the mountainous Afghan border is difficult to patrol. Trump may have leverage with Pakistan, which sought a $10 billion currency swap, and Turkey, which wants to rejoin the F-35 program. However, experts doubt such a blockade would be effective or trigger internal unrest.

Secondary Tariffs

Trump has threatened tariffs on countries trading with Iran, though the Supreme Court has struck down the legal basis for such taxes. A Senate-passed Russia sanctions bill includes new Iran measures and would grant Trump tariff powers. The bill faces an uncertain path in the House, where there is bipartisan concern over the tariff provisions.