By Doina Chiacu and Daphne Psaledakis
WASHINGTON (Reuters) - The United States and six Gulf countries agreed to jointly impose sanctions on 25 corporations, banks and individuals linked to Iran's support for militant networks including Hezbollah, the U.S. Treasury Department said on Wednesday.
The blacklisted targets were announced by the Terrorist Financing Targeting Center (TFTC) nations - which also include Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates.
U.S. Treasury Secretary Steven Mnuchin made the announcement as part of a trip to visit several of these Middle East allies to bolster their support for increasing pressure on Iran.
All 25 targets were previously under financial sanctions imposed by the United States.
"The president couldn't be more clear that we are executing a maximum pressure campaign on Iran," Mnuchin told Reuters in an interview in Riyadh. "This is about stopping a bad actor."
In Jerusalem on Monday, Mnuchin said the United States would increase economic pressure on Iran over its nuclear program.
Sanctions reimposed on Tehran by President Donald Trump after he withdrew the United States from world powers’ 2015 nuclear pact with Tehran have dried up Iranian oil revenue and cut Iranian banks' ties to the financial world.
Mnuchin said the sanctions aimed at halting Iranian oil shipments were not hurting the global economy, adding that oil markets were well-supplied with additional production from Saudi Arabia, the United States and other countries.
Tensions between the United States, its Gulf allies and Iran spiked in recent months after attacks on oil tankers and a September air strike on Saudi oil facilities, which the United States blamed on Iran, but that Tehran has denied.
Twenty-one of the targets announced on Wednesday comprised a vast network of businesses providing financial support to the Basij Resistance Force, a paramilitary group that the U.S. Treasury says works for Iran's elite Islamic Revolutionary Guard Corps (IRGC).
A senior Treasury official said the group attacks demonstrators and students, recruits child soldiers and engages in torture.
The Treasury said shell companies and other measures were used to mask Basij ownership and control over multibillion-dollar business interests in Iran’s automotive, mining, metals, and banking industries, many of which operate across the Middle East and Europe.
Four individuals targeted were Hezbollah-affiliated and help coordinate the group's operations in Iraq, it said.
Earlier this month, Financial Action Task Force (FATF) - the international body that sets standards on combating terrorist financing - said it had given Iran a final deadline of February 2020 to comply with international norms, after which it would urge members to apply counter-measures.
U.S. Secretary of State Mike Pompeo on Wednesday welcomed the move by Paris-based FATF, saying in a statement that the IRGC "continues to engage in large-scale, illicit, financing schemes to fund its malign activities."
(Additional reporting by David Lawder in Riyadh; Editing by Mary Milliken, Jonathan Oatis and Bill Berkrot)