Russia is at risk of being formally declared in default within weeks after failing to make a dollar payment to its lenders, one of the world’s biggest credit agencies has said. 

Moody’s warned the country is in danger of failing to repay its foreign debts for the first time since the Bolshevik revolution as sanctions bite in the wake of President Vladimir Putin’s invasion of Ukraine.

Moscow sought to pay $650m (£497m) of interest on its bonds in roubles earlier this month, in violation of a contract stating the money must be paid in dollars.

This kicked off a 28-day grace period, after which the country may be deemed to have defaulted by ratings agencies in a severe blow to its reputation. Being in default would also badly damage Russia’s ability to raise more cash in future years, even if sanctions are lifted.

Moody’s said that the roubles payment means that Russia “may be considered a default under Moody’s definition if not cured by 4 May, which is the end of the grace period”.

The agency added: “The bond contracts have no provision for repayment in any other currency other than dollars.”

Some Russian eurobonds issued after 2018 allow payments in roubles under some conditions. However, those issued before 2018 – including the two which the Kremlin tried to repay on April 4 – do not.

The agency said: “Moody’s view is that investors did not obtain the foreign-currency contractual promise on the payment due date.”

The Russian finance ministry did not respond to a request for comment. Finance Minister Anton Siluanov told the Izvestia newspaper earlier this month that if Russia is forced into a default, it will take legal action.