Sweeping U.S. sanctions on Russia's oil industry will make it more expensive for Moscow to sell its oil and complicate sea-borne crude exports due to restrictions on tankers, analysts and traders said on Monday.

A fresh wave of U.S. sanctions against Russia’s oil industry threatened to disrupt global supplies, sending crude prices to their highest in more than four months.

Oil settled near $79 a barrel — a five-month high — as a fresh wave of US sanctions against Russia’s energy industry threatened to crimp supplies from one of the world’s top producers.Most Read from BloombergThese Homes Withstood the LA Fires.

Energy producers have rushed to lock in oil prices since the United States announced its harshest sanctions yet on Russian energy trade on Friday, which sent oil prices surging to multi-month highs, market participants said.

The Biden administration has imposed some of its toughest sanctions yet on Russia, in a move designed to hit Moscow's energy revenue that is fuelling its war in Ukraine. The measures target more than 200 entities and individuals ranging from traders and officials to insurance companies, as well as hundreds of oil tankers.

Oil prices slipped on Tuesday from the previous day's four-month highs but the market remained supported by continuing focus on the impact of new U.S. sanctions on Russian oil exports to key buyers India and China.

At least 65 oil tankers have anchored in various locations around the world, including off the coasts of China and Russia, since the US announced a new package of sanctions on January 10, Reuters reports.

At least 65 Russian oil tankers have been forced to anchor and suspend shipments following the imposition of the toughest U.S. sanctions yet on Russia’s oil and gas sector. The sanctions were announced on January 10,