Image at Jam Petrochemical Company in Iran, one of the entities placed on the US sanctions list. (Source: Tapico)

The move adds oil and petrochemicals to a US executive order targeting key sectors of Iran's economy, in response to the Iranian government's funding of its nuclear and missile programs.

The US Treasury Department has identified 16 entities (sanctioned) and 17 vessels as blocked assets, for their involvement in the transportation of petroleum and petrochemical products, supporting the National Iranian Oil Company.

Analysts have outlined a range of threats and possible scenarios related to the current tensions between Israel and Iran. Increased US sanctions on Iran could cut oil exports from the Middle Eastern country by at least half a million barrels per day. Israeli attacks on Iranian oil facilities, including refineries, could disrupt Tehran’s energy exports as well as its domestic fuel supplies.

Any Israeli attack that disrupts Tehran's 1.7 million barrels of oil exports per day would have consequences for global energy markets, according to the Financial Times .