WASHINGTON, June 28, 2024 (BSS/AFP) - The United States on Thursday announced sanctions against shipping companies for transporting Iranian oil, saying it was a response to Tehran's nuclear "escalation," on the eve of presidential elections in the Islamic republic.

"Over the past month, Iran has announced steps to further expand its nuclear program in ways that have no credible peaceful purpose," Secretary of State Antony Blinken said in a statement.

He said the United States was imposing the sanctions "in response to these continued nuclear escalations," saying, "We remain committed to never letting Iran obtain a nuclear weapon, and we are prepared to use all elements of national power to ensure that outcome."

The State Department announced sanctions on three shipping companies, all based in the United Arab Emirates, for allegedly transporting Iranian oil as well as 11 associated vessels.

The sanctions block any assets of the companies in the United States and criminalize US transactions with them.

The United States already has a sweeping unilateral ban on other countries buying Iranian oil, imposed by former president Donald Trump when he withdrew from a nuclear deal.

President Joe Biden's administration initially said it would restore the 2015 deal but gave up after exhaustive negotiations with Tehran, major protests inside Iran and, more recently, tension over Iran's support for Palestinian militants Hamas.

The UN nuclear watchdog said earlier this month that Iran is further expanding its nuclear capacities, with Tehran informing the agency that it was installing more cascades at enrichment facilities.

Iran's cleric-led government denies seeking a nuclear weapon. Iran on Friday holds elections for president after conservative Ebrahim Raisi was killed in a helicopter crash.