The latest coupon payments on Russia's sovereign bonds have been halted, Reuters reports, citing a source, bringing the situation closer to a historic default.

According to the source, the latest coupon payments on sovereign bonds have not received permission from the US Department of the Treasury to be processed by correspondent bank JPMorgan (JPM). Payments were due on bonds maturing in 2022 and 2042.

The correspondent bank processes coupon payments from Russia, sending them to the paying agent for distribution to foreign bondholders.

Earlier coupon payments on sovereign bonds were processed, the sources said.

A US Treasury Department spokesman also confirmed that some payments are no longer allowed.

Today is the deadline for Russia to make another payment on the debt, the spokeswoman said.

Starting today, the US Treasury does not authorize any payments on dollar debt from Russian government accounts at US financial institutions. Russia must choose between depleting its remaining valuable dollar reserves, generating new revenue, or defaulting.

The country has a 30-day grace period to make the payment, the source said.

Russia, which has 15 international bonds outstanding with a par value of about $40 billion, has so far managed to avoid defaulting on its international debt despite unprecedented Western sanctions. But the task is getting more difficult. If Russia fails to make any of its forthcoming bond payments within the predetermined time frame, or pays in rubles where dollars, euros, or other currencies are indicated, it will constitute a default.

While Russia is unable to access international debt markets due to Western sanctions, a default would deny it access to those markets until creditors are fully repaid and any default-related court cases are settled.