WASHINGTON -- The United States on Tuesday slapped sanctions on a group of front companies allegedly controlled by Iran's leadership.

The Department of Treasury said the Execution of Imam Khomeini' s Order (EIKO) and the 37 companies it oversees on behalf of the Iranian government operate in various sectors of the Iranian economy and around the world, generating billions of dollars in profits for the Iranian government each year.

"In addition to generating revenue for the Iranian leadership, EIKO has been tasked with assisting the Iranian government's circumvention of U.S. and international sanctions," the department said in a statement.

"Even as economic conditions in Iran deteriorate, senior Iranian leaders profit from a shadowy network of off-the-books front companies," the Treasury's Under Secretary for Terrorism and Financial Intelligence David Cohen was quoted as saying.

The sanctions against the companies, which spread across the world, bar American citizens and companies from doing business with them. And foreign financial institutions dealing with them risk being denied access to the U.S. financial system.

A day earlier, President Barack Obama signed a new executive order authorizing sanctions against Iran's currency and its auto industry in his administration's continuous efforts to force the Islamic republic to stop its uranium enrichment activities, which the West suspects are used to produce nuclear weapons.

Iran has denied the charge, insisting on the peaceful nature of its nuclear program.