Washington on Friday imposed a raft of new sanctions on Russia over its alleged interference in the 2016 US presidential election, as well as its interventions in Ukraine and Syria.
Here are three key groups that will be hit in a move that targets those close to President Vladimir Putin:
A number of big-name Russian oligarchs have been included in the sanctions list, meaning any assets they hold in areas under US jurisdiction could be frozen.
The highest-profile of these is Oleg Deripaska, who has managed to stay on the right side of Putin and build up a gigantic business empire.
Deripaska was once an associate of US President Donald Trump's former campaign director Paul Manafort.
Others on the list are Kirill Shamalov, reportedly Putin's former son-in-law, and Suleiman Kerimov, a billionaire and senator who is currently being investigated for tax fraud in France.
"We are designating Kirill Shamalov, who married President Putin's daughter in 2013," said a senior US administration official.
"Within 18 months of his marriage he acquired a large portion of shares of a Russia based energy company. A year later he was able to borrow more than one billion dollars through a loan from Gazprom bank, a state-owned entity, subject to sectoral sanctions."
Washington has put Russia's state arms exporter Rosoboronexport on the sanctions list, meaning any country that trades with Russia's defence or intelligence sectors will also be targeted.
With India set to sign a deal with Moscow for two S-400 air defence systems, New Delhi could be in the firing line -- but commentators have suggested the US will be loath to undermine this relationship.
Putin has made the development of the military-industrial complex one of his priorities since he arrived in power 18 years ago, and this year boasted of "invincible" weapons Russia was developing.
"The fact that Rosoboronexport is the target confirms the true aim of the sanctions," Russia's state-run holding company Rostec said.
"All this big talk and accusations are just an excuse to drive Russia out of the world arms market."
Among the top officials targeted are several members of the "siloviki", representatives of the army and the security services close to Putin.
These include Nikolai Patrushev, the chief of Russia's security council who formerly succeeded Putin as head of the FSB security service, as well as interior minister Vladimir Kolokoltsev.
Alexei Dyumin, formerly Putin's personal bodyguard and now governor of the central Tula region, is also targeted, along with Alexander Zharov, the head of communications watchdog Roskomnadzor.