Russian oil company Gazprom Neft, a subsidiary of the energy giant Gazprom, has been given 45 days to divest from its ownership of the Serbian oil company NIS following new US sanctions targeting the Russian oil sector.

The sanctions also target Russia's "shadow fleet" of oil tankers.The United States and the United Kingdom imposed further sanctions on Russia's energy sector on Friday in an attempt to curb funding for Moscow's full-scale invasion of Ukraine.

The UK has imposed sanctions on Russian companies Gazprom Neft and Surgutneftegaz for the first time. The restrictions will affect Russia's oil revenue, according to the UK government's press service.