The US has imposed sanctions on the Petroleum Industry of Serbia (NIS), the operator of Serbia's only refinery.

NIS, majority-owned by Russia’s state oil monopoly Gazprom Neft, distributes a large share of the country’s oil.

The company supplies roughly 80% of Serbia's diesel and petrol demand and more than 90% of jet fuel and heavy fuel oil, reported Reuters.

NIS was unable to secure a further postponement of the US measures, although it said it had stored sufficient stocks to maintain operations for a period.

Late last month, the US Treasury’s Office of Foreign Assets Control postponed sanctions on NIS, initially set for 1 October, by eight days.

Its Pancevo refinery near Belgrade has a capacity of around 4.8 million tonnes per annum (mtpa).

Bojana Radojevic, the company’s retail director, said petrol stations would keep operating as normal.

Radojevic said: “There are no restrictions when it comes to the quantities customers can purchase.”

There could be issues accepting foreign bank cards at filling stations, but cash payments in local currency would be accepted.

Serbia is heavily dependent on Russian energy, receiving most gas and oil via pipelines through Croatia and neighbouring states.

Crude imports to Serbia are carried on the JANAF pipeline from Croatia. JANAF has been granted a US licence extension allowing it to transport crude to Serbia until 15 October.

However, it remains unclear whether NIS would be permitted to accept further deliveries.

The US originally applied sanctions to parts of Russia’s oil sector earlier this year.

Serbia, which is formally seeking EU membership, has not joined Western sanctions on Russia following Moscow’s invasion of Ukraine, citing its reliance on Russian gas supplies.