Russia may respond to any U.S. confiscation of its currency reserves frozen in the West by seizing the assets, including property and cash, of U.S. citizens and investors in Russia, Dmitry Medvedev, a senior security official, said on Saturday.

The U.S. House of Representatives has passed a bill allowing the Biden administration to confiscate Russian assets held in American banks and transfer them to Ukraine, something the Kremlin has said would be illegal and trigger retaliation.

In response to Russia’s war in Ukraine, the United States and its allies prohibited transactions with Russia’s central bank and finance ministry and blocked about $300 billion of sovereign Russian assets in the West, most of which are in European not American financial institutions.

The Group of Seven (G7) major democracies is also looking at what it may be able to do around the frozen Russian assets.