Investing.com -- The Trump administration announced new sanctions on Iran on Thursday that target individuals, networks and 17 vessels involved in transporting crude oil, oil products and petrochemicals, according to the Treasury Department.

The sanctions fall under the department's "Operation Economic Outcast," which seeks to reduce Tehran's funding for war efforts, missile construction, cyberattacks and the Islamic Revolutionary Guard Corps.

A Treasury official told reporters the action represents the most substantial impact on Iran's remaining illicit maritime infrastructure by neutralizing most of the shadow fleet. The official said the department is cutting off the regime's last major source of illicit revenue and strengthening international pressure to hold Tehran accountable.

The move increases pressure on Iranian oil sales following the US re-imposition of its blockade of Iranian ports on July 14, which came after a memorandum of understanding between Tehran and Washington broke down.

Iran has approximately 20 million barrels of crude oil remaining on vessels outside of the blockade, a Treasury official said. Global oil consumption stands at about 100 million barrels per day.