The United States on Friday imposed additional sanctions related to the price cap on Russian oil, targeting three entities and three oil tankers as Washington seeks to close loopholes in the mechanism designed to punish Moscow for its war in Ukraine.

The U.S. Treasury Department accused those targeted on Friday of using Western maritime services such as transportation, insurance, and financing while carrying Russian crude oil above the $60-per-barrel price cap.

The Group of Seven rich countries, the European Union and Australia imposed the $60-per-barrel cap last December on seaborne exports of Russian crude. The mechanism bans Western companies from providing the services for oil sold above the cap.

The Treasury said that the vessels the NS Champion, Viktor Bakaev and HS Atlantica carried Russian Urals crude above $70 per barrel.

Russia’s embassy in Washington did not immediately respond to a request for comment.

The Treasury said in a statement that the vessels used “U.S.-person” services while transporting the Russian-origin oil, without providing more details.

The agency said United Arab Emirates-based Sterling Shipping is the registered owner of the NS Champion.

UAE-based Streymoy Shipping Limited is the registered owner of the Viktor Bakaev, it said, and Liberia-based HS Atlantica Ltd is the registered owner of the HS Atlantica.

Sterling Shipping did not immediately respond to a request for comment. Reuters could not immediately find contacts for the other two companies.

The sanctions block all property and interests of the listed tankers and owners in the U.S. or in possession of U.S. persons, and those assets have to be reported to the Treasury’s Office of Foreign Assets.

It was Washington’s latest sanctions action cracking down on the shipment of oil above the price cap as the U.S. seeks to enforce the punitive measures it has imposed on Russia over its invasion of Ukraine last year.

“Enforcement of the price cap on Russian oil is a top priority for the United States and our Coalition partners,” Treasury Deputy Secretary Wally Adeyemo said in the statement.

“By targeting these companies and their ships, we are upholding the dual goals of the price cap by restricting Russia’s profits from oil while promoting stable global energy markets.”

The Treasury also issued a general license authorizing limited safety and environmental transactions involving those targeted, including transactions necessary for the safe docking and anchoring of the blocked vessels, until Feb. 29.

Source: Reuters reported by Daphne Psaledakis and Timothy Gardner and edited by Chizu Nomiyama, Jonathan Oatis and Frances Kerry