“The United States is taking sweeping action against Russia’s key source of revenue for funding its brutal and illegal war against Ukraine,” Secretary of the Treasury Janet Yellen said in a statement.

She added that these sanctions build on and strengthen the U.S. effort to disrupt Russian energy revenues.

The State Department is blocking two active liquified natural gas projects, a large Russian oil project and third-country entities supporting Russian energy exports.

It is also designating senior officials at Rosatom, Russia’s state atomic energy corporation as well as numerous Russia-based oilfield service providers.

The Treasury Department said in a statement the 183 vessels targeted by the new sanctions round are “an unprecedented number of oil-carrying vessels, many of which are part of the ‘shadow fleet,’ opaque traders of Russian oil.”

The sanctions announced Friday include vertically integrated Russia-based oil companies Gazprom Neft and Surgutneftegas.

Treasury said Britain is joining the United States in the new sanctions effort against those Russian oil producers.

The U.S. sanctions also targeted Russia-based maritime insurance providers Ingosstrakh insurance company and Alfastrakhovanie Group.

Nine Russian oil trading companies were included in the new sanctions, along with 14 Russian nationals serving as energy officials.

Sanctioned entities described by Treasury as ‘opaque traders of Russian oil’ included Black Pearl Energy Trading LLC and Black Pearl employee Alexander Valeryevich Nemirovskiy.

In a statement, the Treasury Department said the new sanctions “further implement commitments made by G7 leaders to reduce Russian revenues from energy and other commodities.”