Washington: The United States is imposing export controls against Russia's oil refining sector and targeting 91 entities across 10 countries that support the Russian military in response to the latter's operation in Ukraine, the Commerce Department said on Friday.

"The new regulations target Russia's oil refining sector with new stringent export controls and identify 91 entities that support Russian military activities. These actions will further restrict access to U.S. commodities, software, and technology as part of our ongoing efforts to degrade Russia's ability to acquire the items it needs to sustain its military aggression," the Commerce Department said in a press release.

The US also added 91 entities in 10 countries to the Commerce Department's Entity List based upon their involvement in, contributions to, or support of the Russian security services, military and defence sectors, the release said.

"These entities are located in Russia (81), United Kingdom (3), Estonia (3), Spain (2), Malta (2), Kazakhstan (1), Latvia (1), Belize (1), Singapore (1), and Slovakia (1) (NOTE: Total entries is 96 as some entities operate in multiple countries)," the release added.

Among those sanctioned are Russian Space Systems, Amur Shipbuilding Factory, other shipyards, scientific research institutes and other companies.

Last week, Russia launched a "special operation" in Ukraine in response to calls from the Donetsk and Luhansk people's republics to defend themselves against intensifying attacks by Ukrainian troops. The Russian Defence Ministry said the operation is targeting Ukrainian military infrastructure only and the civilian population is not in danger.

In response, the US and its allies have rolled out comprehensive sanctions, including restrictions on the Russian central bank, export control measures, SWIFT cut-off for select banks, and closure of airspace to all Russian flights.