Originally Published: 01 AUG 22 12:36 ET

By Jennifer Hansler, CNN

(CNN) -- The United States on Monday unveiled a new tranche of sanctions targeting "illicit" support for the Iranian oil industry as prospects for reviving the Iran nuclear deal continue to dim.

In a statement, Secretary of State Antony Blinken said the "United States has been sincere in pursuing a path of meaningful diplomacy to achieve a mutual return to full implementation of the Joint Comprehensive Plan of Action," which is the formal name of the 2015 Iran nuclear deal.

"Until Iran is ready to return to full implementation of the JCPOA, we will continue to use our sanctions authorities to target exports of petroleum, petroleum products, and petrochemical products from Iran," Blinken said.

Efforts to salvage the deal -- from which the US withdrew in 2018 under former President Donald Trump -- have been unsuccessful. Iran has increasingly violated the terms of the agreement and grown its nuclear program. A round of indirect talks between the US and Iran ended in late June without any progress. Both Washington and Tehran have blamed the other for the failure to revive the agreement.

Blinken said the Biden administration is sanctioning "six entities facilitating illicit transactions related to Iranian petroleum as well as petroleum and petrochemical products, key sources of revenue for the Iranian government."

The two entities sanctioned by the State Department are Pioneer Ship management PTE LTD, "a company that managed one liquified petroleum gas tanker, for serving as the commercial manager for a vessel that transported Iranian petroleum products" and Golden Warrior Shipping, Co. Ltd., which "has engaged in transactions related to Iranian petroleum and petroleum products, to include providing logistical support to the Iranian petroleum trade."

"The Department is further identifying the vessel Glory Harvest as blocked property of Golden Warrior Shipping Co. Ltd," Blinken said.

The US Treasury Department sanctioned "four entities that support Iran's Persian Gulf Petrochemical Industry Commercial Co.," which is under US sanction and "continues to be involved in the sale of Iranian petroleum products and petrochemical products abroad," Blinken said.

According to the Treasury Department, Monday's sanctions build on those issued in June and July. They target a company based in the United Arab Emirates called Blue Cactus Heavy Equipment and Machinery Spare Parts Trading L.L.C., as well as Hong Kong- and Malaysia-based Farwell Canyon HK Limited, Shekufei International Trading Co., Limited, and PZNFR Trading Limited, all of which supported PGPICC, according to the US Treasury.