The latest measures are part of the Trump administration's broader effort to restrict Iran's access to international markets and reduce the country's ability to generate revenue through oil exports and other economic activities.
US Treasury officials say the campaign is designed to target networks that help Iran obtain sensitive technology, move oil through international shipping networks and generate funds for activities Washington considers a threat to US national security.
Who is being targeted?
The new sanctions cover individuals and organisations located in Iran as well as several other countries. The targets include networks allegedly involved in procuring technology and equipment for Iran's military programmes.
Several companies connected to China and Hong Kong have also been targeted. US authorities accuse some of these businesses of helping Iranian entities obtain dual-use technology and other equipment.
Pressure on Iran's oil trade
Iran's oil industry remains one of the central targets of the new sanctions. Washington says a network of brokers, companies and vessels has helped Iranian oil reach international buyers despite existing restrictions.
The measures also target vessels described as part of Iran's so-called "shadow fleet". These ships are accused of helping transport Iranian oil while attempting to avoid international sanctions and restrictions.
Five key sectors under greater pressure
The latest US campaign goes beyond individual companies and people. It also increases the risk of sanctions involving several major sectors connected to Iran's international economic activity.
- Digital assets and cryptocurrency
- Technology
- Gold and precious metals
- Aviation
- Shipping and maritime trade
US officials say these areas can provide channels through which Iran attempts to maintain access to international finance and continue economic activity despite sanctions.
Why the sanctions matter
The latest measures represent a broader attempt by Washington to weaken Iran's financial networks rather than focusing only on individual Iranian institutions.
The United States has also warned countries and companies that continue doing business with Iran that they could face additional economic consequences. This could increase pressure on international companies that have commercial relationships with Tehran.
China's role
China's position is particularly important because it remains a major trading partner for Iran and a significant destination for Iranian oil.
Any attempt by Washington to further restrict Iran's trade with China could therefore create additional diplomatic and economic tension between the United States and China.
What happens next?
The effectiveness of the new sanctions will depend partly on how international businesses and Iran's major trading partners respond. Tehran has repeatedly developed alternative financial and trading channels to reduce the impact of US restrictions.
Washington, meanwhile, appears determined to increase economic pressure on Iran and restrict the country's access to international revenue sources. The latest sanctions could therefore become another major point of tension in the already strained relationship between the two countries.
Bottom line
The new US sanctions mark a significant expansion of Washington's economic pressure campaign against Iran. With oil, technology, shipping, aviation and financial networks increasingly under scrutiny, the measures could have consequences beyond Iran and affect companies and markets connected to the country's international trade.
Sources: US Department of the Treasury, Al Jazeera, Reuters