Russia's central bank has moved to stop the national currency's nosedive by saying it stands ready to intervene in markets.

The ruble plummeted to an a new low of 48.7 rubles a dollar Friday before bouncing back on reports about the bank's emergency board meeting. After the bank issued its statement, the currency stabilized at around 46.4 rubles a dollar.

In the statement, the central bank defended its decision earlier this week to dial back its support for the currency, which was costing it millions, sometimes billions, of dollars a day.

At the same time, it voiced Friday its readiness to increase market interventions and use other instruments to prevent the ruble from plunging further.