The cap is intended to cut Russia's oil revenues while keeping Russian crude on the market by denying insurance, maritime services and finance provided by the Western allies for tanker cargoes priced above a fixed dollar-per barrel cap.The cap is a concept promoted by the United States since the EU first laid out plans in May for an embargo on Russian oil to punish Moscow for its invasion of Ukraine.India's finance and energy ministries were not available for comment on Yellen's remarks, but other officials have said they were wary of the untested price cap mechanism.We believe most countries are comfortable with it and it is in no one's case that Russian oil should go offline," one Indian government official told Reuters, speaking on condition of anonymity.Yellen said that even with Russian tankers, Chinese tankers and a "shadow" fleet of older, decommissioned tankers and re-flagged vessels, "I just think they will find it very difficult to sell all the oil that they have been selling without a reasonable price.""