Commercial vessels and oil tankers preparing to transit through the Strait of Hormuz, one of the most critical strategic waterways for global trade flows, maintain their wait in the Gulf of Oman, on June 17, 2026.

Shady Alassar | Anadolu | Getty Images

The U.S. Treasury Department on Tuesday revoked its authorization of Iranian oil sales after a series of attacks on tankers in the Strait of Hormuz this week.

"Iran will only reap benefits if they exhibit good behavior," a U.S. official told CNBC. "Iran's actions in the Strait were wholly unacceptable to the United States and will be met with consequences."

The threat to ships crossing Hormuz increased to "severe" Tuesday after attacks on a liquefied natural gas tanker, an oil supertanker and an unspecified third tanker, according to the Joint Maritime Information Center, a naval group led by the U.S. that provides security updates to merchant vessels in the Middle East. Hostile action by Iran is likely, the center warned mariners in a notice.

Treasury had waived its sanctions on Iranian oil sales through August 21 after the U.S. and Iran inked an interim deal to reopen Hormuz last month. The waiver allowed the import of Iranian oil to the U.S. and payment to Tehran in dollars. Critics had slammed the waiver as major concession to the Islamic Republic.

Iran promised ships safe passage through Hormuz under the deal with the U.S. But Tehran has insisted that vessels must use a northern route under its control. It has attacked ships that use a U.S. Navy protected route along Oman's coast.