The United States said Tuesday that the Islamic Republic of Iran is to blame for a sabotage attack on two Saudi oil tankers and two other vessels off the coast of the United Arab Emirates earlier this month.

U.S. Acting Defense Secretary Patrick Shanahan made the comments after he and U.S. Secretary of State Mike Pompeo briefed members of Congress behind closed doors on the heightened tensions with Iran.

Shanahan told reporters outside the Pentagon that the deployment of a U.S. aircraft carrier and B-52 bombers to the Middle East has been an effective deterrent against Iranian aggression, forcing the mullah regime “to recalculate” its behavior.

“That doesn’t mean that the threats that we’ve previously identified have gone away,” added Shanahan. “I think our response was a measure of our will and our resolve that we will protect our people and our interests in the region.”

The latest assessment is that Iran’s elite Islamic Revolutionary Guard Corps (IRGC) used explosives to blow huge holes in the four ships. Each of the vessels had a 5- to 10-foot hole in it, near or just below the water line.

The oil tankers were targeted near the port of Fujairah in the United Arab Emirates, with one of the vessels due to be loaded with Saudi crude oil bound for the United States. The Pentagon warned ships that “Iran or its proxies” could be targeting maritime traffic in the region.

Emirati officials had requested a team of U.S. military experts to aid them in their investigation. Their initial assessment confirmed that Iran or one of its regional terror proxies was behind the attack.

Senior Iranian officials have repeatedly threatened to close the strategic Strait of Hormuz in response to the U.S. decision to end sanction waivers on Iranian oil imports and to designate the IRGC as a foreign terrorist organization.

The Strait of Hormuz is the world’s most important oil transit choke point.

[Photo: Financial Times / YouTube]