Britain will cut off Russian banks from sterling markets and clearing payments, and the United States is taking similar action on the dollar, Prime Minister Boris Johnson said on Thursday.

"These powers will enable us totally to exclude Russian banks from the UK financial system, which is of course by far the largest in Europe, stopping them from accessing sterling and clearing payments through the UK," Johnson told parliament.

"And with around half of Russia's trade currently in US dollars and sterling, I'm pleased to tell the House that the United States is taking similar measures."