Iran has spent $16 billion on its “militias” in Iraq and Syria, U.S. Special Representative for Iran Brian Hook told Saudi-owned Al Arabiya TV on Thursday.
He did not give more details on the militias or say when Iran had spent the money.
During the interview also he confirmed that Washington would continue to impose sanctions on Tehran, saying that they were a result of "destabilizing behavior in the region."
During one year of sanctions, Iran's oil exports fell from 2.5 million a year to 120,000, "indicating a total collapse of the oil industry," Hook said, adding that U.S. sanctions also targeted the petrochemical and industrial and precious metals sectors.
Hook further pointed the finger at Iran for being behind attacks on Saudi oil facilities in September, which Tehran has denied, adding that Iran is targeting Saudi Arabia from the north and south of the country.
The attacks on Saudi Arabia damaged the globe's largest crude processing plant and triggered the biggest jump in oil prices in nearly 30 years.
Hook said Washington looks forward to Iraq reducing its economic dependency on Iran. Iraq has seen a wave of mass anti-government protests in past days, a part of which has focused on Iran's grip on the government in Baghdad and its backing of local armed groups.