Russian President Vladimir Putin has signed a decree that temporarily allows overseas creditors to be paid in rubles instead of foreign currencies. The move appears meant to keep Russia from defaulting on its debts.

The decree says payments in rubles will be made at an exchange rate set by the Russian central bank. The measure is for debts held by countries that Moscow says have engaged in "hostile" activities against Russia.

The move comes as severe economic sanctions by the West have sent the ruble tumbling.

Ratings agency Moody's announced on Sunday that it lowered the credit rating for long-term Russian government bonds to "Ca," which indicates "at or near default."

Moody's says it has "severe concerns over Russia's willingness and ability to pay its debt obligations."