Russia is likely to default on its debts, as it was warned by a leading ratings agency.
Russia was slashed to almost the bottom of the scale by the ratings agency just days after it was demoted from investment status.
It is the latest blow to the country's credit rating.
Moscow said its bond payments may be affected by sanctions.
The further ramping up of sanctions, and proposals that could limit trade in energy, increase the probability of a policy response by Russia that includes at least some non-payment of its debt obligations.
The US and UK said they will ban Russian oil as they step up the economic response to the invasion of Ukraine.
US President Joe Biden said the move targeted the main arteries of Russia's economy.
The European Union will no longer rely on Russian gas.
Experts warn that the price of oil and natural gas will go up on global markets because of the measures aimed at hitting Moscow's finances.
Moscow told investors on Sunday that it would continue to service its debt.
It warned that international sanctions could limit its ability and willingness to meet its obligations.
The finance ministry said in a statement that the actual possibility of making such payments to non-residents will depend on the limiting measures introduced by foreign states.
The first major default on the country's bonds since the 1917 Bolshevik revolution is possible if Russia fails to make payments on its debt.
Moody's Investors Service and S&P Global Ratings have recently slashed their assessments of Russian debt.
The country's debt is now considered to be below investment grade by three of the world's major ratings companies.
S&P said the move followed measures it believed would increase the risk of default.
Oliver believes a default on Russian debt was already occurring.
Foreign investors are selling it at fire sale prices and it will only service it in roubles. The global exposure to it is relatively low.
The Russian rouble has hit a record low as countries around the world impose harsher sanctions on the country.
Russia's central bank doubled its interest rate last month in an attempt to stop the depreciation of its currency.
McDonald's, Coca-Cola, and Starbucks are some of the global brands that have stopped business in Russia due to the invasion of Ukraine.