Russia is due to pay $117 million (¥13.83 billion) in interest on two dollar-denominated sovereign bonds on Wednesday — the first such payments since its invasion of Ukraine, which sparked a raft of sanctions from Western capitals and countermeasures from Moscow.

The diplomatic standoff and economic curbs have sparked questions over whether and how Russia will make the payment, raising the specter of its first major external debt default since 1917, when Bolsheviks failed to recognize Tsarist debt in the wake of the revolution.

Here is what we know and do not know about Russia's debt and its repayment: