The two central and east European (CEE) states were together buying around 2mt/year of oil from the privately owned Lukoil just before the ban hit last Wednesday, Szijjarto said.

“We have been able to stabilise the situation with temporary solutions, but these will not be enough even for the near future,” Szijjarto warned during a news briefing. 

Hungary relies on Russian imports for 60-80% of its oil consumption, with half of this supplied by Lukoil, data from the country's trade administration shows.

Slovakia’s prime minister Robert Fico told local media that Ukraine’s move, which aims to curb Russia’s revenue stream from oil, was “unfriendly but also pointless”. He added that the ban does not cause any particular damage to the Russian economy, but creates problems for some EU member states.

"No reason for panic"

However, Bulgarian energy expert Martin Vladimirov said on LinkedIn that that the authorities of the affected countries have been stoking a “panic about security of supply”.

“This is simply wrong and serves the Kremlin well,” he said.

He noted that Bulgaria also tried to use “fake arguments” about its excessive dependence on Russian oil to preserve a derogation from the EU ban on Russian oil imports until a series of analyses proved that it could wean itself off the Russian oil completely.

“The same [applies to] Hungary and the other central European countries with exemptions from the Russian oil ban. There is no reason for panic,” Vladimirov noted.

“Although the derogations were given to Druzhba-dependent countries, so that they prepare for a full Russian oil phaseout, they have done little to complete the transition, and instead have doubled down on using Russian crude,” he said.

Vladimirov noted that the Adriatic pipeline from Croatia’s Janaf-operated Omisalj terminal can supply refineries in Croatia, Hungary, the Czech Republic and Slovakia.

“The pipeline’s installed capacity of 400,000 b/d [barrels per day] is more than enough to cover their normal operating needs at [an] about 80% utilisation rate,” Vladimirov wrote.

The Croatian state-owned oil pipeline operator confirmed its ability to supply the region in a statement for Montel on Monday.

"At this moment, Janaf is already in a position to meet all the crude oil transportation needs of its Central European partners,” a spokesperson for the company said.

“The use of polymer allows us to increase the capacity of the pipeline to the Hungarian border to the level of 14 million tonnes annually, which fully meets the needs of [Hungarian gas and oil company] Mol's refineries,” she added.

Additionally, the Transalpine pipeline connecting Trieste port in Italy to Austria, southern Germany and the Czech Republic offers further alternative oil supply routes, and connecting the Austrian refinery near Vienna and the Slovak refinery near Bratislava requires minimal infrastructure investment due to their geographical proximity, Vladimirov noted.