WASHINGTON: The United States and its allies are "disarming Fortress Russia" with new sanctions that cut off key banks from the SWIFT financial transactions network and target Russia's central bank, a senior Biden administration offial said on Saturday.

The actions are aimed at preventing Russian President Vladimir Putin from using $630 billion in central bank foreign currency reserves in the invasion of Ukraine and to defend a plunging rouble.

"Putin's government is getting kicked off the international financial system," the official said.

READ MORE: Latest development on Ukraine-Russia