Behind the scenes, the Treasury and State Departments have urged banking giants, including JPMorgan and Citigroup, to continue doing business with certain strategic Russian firms.

In particular, we are talking about money transfers and conversion into dollars for Gazprom, Uralkali or PhosAgro.

This is done in order to "avoid a global economic catastrophe," adds Bloomberg.

In June, the US Treasury allowed until December 5 to carry out operations with the Bank of Russia, VEB, Otkritie Bank, Sovcombank, Sberbank, VTB and Alfa-Bank on energy, despite the sanctions.