WASHINGTON -- The Obama administration on Monday expanded sanctions against Iran to target the Islamic republic's currency for the first time as well as its auto industry.

President Barack Obama approved a new executive order allowing tightening sanctions on Iran in his administration's continuous efforts to force the country to stop its uranium enrichment activities.

Under the order, foreign financial institutions will be hit with sanctions for making "significant" transactions in the purchase or sale of the Iranian rial, or for maintaining " significant" accounts outside Iran denominated in the Iranian currency, which has reportedly lost half of its value since the beginning of 2012 as a result of U.S. sanctions.

Sales of goods or services for the manufacturing or assembling in Iran of light and heavy vehicles, including passenger cars, trucks, buses, minibuses, pick-up trucks and motorcycles, are subject to sanctions as well.

"The steps taken today are part of President Obama's commitment to prevent Iran from acquiring a nuclear weapon, by raising the cost of Iran's defiance of the international community," White House spokesman Jay Carney said in a statement.

"Even as we intensify our pressure on the Iranian government, we hold the door open to a diplomatic solution that allows Iran to rejoin the community of nations if they meet their obligations," he added.

Iran insists on the peaceful nature of its nuclear program, while the West regards it as a cover for making nuclear weapons.