Hungary has banned its gas transmission system operator from holding auctions for shipments to Ukraine in the third quarter, as it moves to wind down supplies to its neighbor in a dispute over oil flows.

Prime Minister Viktor Orban said on Wednesday that Hungary would gradually stop sending natural gas to Ukraine until oil flows resume to Hungary through the Druzhba pipeline.

Hungary and Slovakia, whose leaders are outliers in the European Union for maintaining relations with Moscow, blame Kyiv for an outage on the Druzhba pipeline that supplies their refineries with Russian crude pumped through Ukraine.

Kyiv says the pipeline was damaged by a Russian drone attack in late January and it is fixing it as fast as it can.

"The transmission system operator cannot announce a ... capacity auction for shipment to Ukraine for the third quarter of 2026," the decree signed by Orban said.

The decree also said that a further 800 million cubic meters of natural gas must be stored in Hungary's storage facilities on top of previously mandated quantities.

A spokesperson for Ukraine's ministry of foreign affairs said on Wednesday that if Hungary halts gas shipment to Ukraine, it will deprive Hungary of more than $1 billion in revenues it got last year.

For March, Ukraine contracted 180 mcm of gas from Hungary, or 28% of its total, an industry source told Reuters earlier this month, slightly less than in February.

Orban also flagged earlier that Hungary could cut electricity exports to Ukraine if oil flows through Druzhba do not resume.

Separately, data from Ukraine's gas transmission operator showed that gas supplies from Hungary would remain at the levels seen in recent days on Thursday.

The data showed that about 8.2 mcm of gas were nominated for supply to Ukraine against 8.3 mcm on Wednesday.

Ukraine plans to receive a total of 24.7 mcm of gas from Hungary, Poland, Slovakia and Romania on Thursday, it showed.