The United States has imposed new sanctions targeting a key financial supporter of Iran’s Supreme Leader Ayatollah Mojtaba Khamenei, along with 13 other individuals and entities, in response to Tehran’s recent attacks on oil tankers in the Strait of Hormuz, according to the U.S. Treasury Department. The move comes amid escalating tensions and ongoing conflict in the region.

The sanctions focus on Ali Ansari, who had previously been sanctioned by the United Kingdom for his involvement in financially backing the Islamic Revolutionary Guard Corps (IRGC) and other Iranian entities. U.S. officials allege that Ansari misappropriated public funds to build an extensive portfolio of real estate and commercial assets abroad, enriching himself, government elites, and the IRGC. Authorities also targeted three Iran-based exchange houses and several foreign “front companies” that reportedly processed billions of dollars annually to facilitate transactions for sanctioned Iranian banks, using complex corporate structures to conceal their activities.

State Department spokesman Tommy Pigott stated that the action aims to sever the financial networks sustaining Iran’s ruling elite, thereby disrupting their ability to access foreign currency and conduct international financial business. Treasury Secretary Scott Bessent added that the department will persist in employing all available tools to isolate Khamenei and senior Iranian officials from the global financial system.

The sanctions were announced on a day marked by a temporary lull following a week of renewed hostilities. During that period, three commercial tankers from Qatar and Saudi Arabia came under Iranian fire, which prompted retaliatory U.S. strikes on Iranian sites. Iran responded with attacks on U.S. military installations in Gulf states. U.S. President Donald Trump declared that the ceasefire previously agreed upon with Iran had ended, although talks were set to continue at Iran’s request.

Iran’s Foreign Minister Abbas Araghchi condemned the sanctions, asserting that they violate Article 9 of the memorandum of understanding reached last month. He characterized the U.S. measures as a breach following a series of other perceived violations. Iran has warned it stands ready for “all-out defense” should the U.S. further contravene the agreement. Top Iranian negotiator Mohammad Baqer Qalibaf declared on Telegram that the conflict would not conclude with Tehran’s surrender.

Analysts pointed to the sanctions as signaling a shift in U.S. policy. Brett Erickson of Obsidian Risk Advisors suggested that Washington is moving away from preserving the existing diplomatic framework and preparing to replace it entirely. Article 9 of the U.S.-Iran accord committed Washington to refrain from imposing new sanctions or deploying additional forces in the region.

The Treasury detailed that Ansari was formerly the owner and director of the now-bankrupt Ayandeh Bank, which was closed by Iranian authorities in October 2025. It also highlighted Ansari’s use of multiple shell companies and bank accounts across various jurisdictions to amass holdings under Smart Global Limited, a Saint Kitts and Nevis-based firm established in 2011 with investments in real estate and commercial properties across Europe and the Gulf.

Meanwhile, diplomatic efforts continued as mediators sought to salvage talks aimed at ending the Middle East conflict that erupted in late February. Amid the fragile ceasefire’s collapse, a Qatari delegation visited Iran, while Tehran’s top diplomat traveled to Oman, emphasizing ongoing attempts to restore dialogue despite escalating incidents.