The Biden administration issued a new round of sanctions Monday targeting the sale of Iranian oil and petrochemical products to East Asia, dialing up the pressure on Iran to resume compliance with the tattered nuclear agreement. 

The Treasury Department sanctioned four companies in Hong Kong, Malaysia and the United Arab Emirates that it said were used by Persian Gulf Petrochemical Industry Commercial Co., one of Iran's largest petrochemical brokers, to facilitate the sale of tens of millions of dollars’ worth of Iranian petroleum and petrochemical products. 

Separately, the State Department took action against two entities — Singapore-based Pioneer Ship management PTE LTD and Hong Kong-based Golden Warrior Shipping — for alleged involvement in Iran's petroleum trade. The department also identified the Panama-flagged vessel Glory Harvest as blocked property of Golden Warrior Shipping. 

Why it matters: The crackdown on Iran’s oil revenue comes as efforts to restore the nuclear agreement, the Joint Comprehensive Plan of Action (JCPOA), have reached an impasse.