By MICHAEL SCHWIRTZ
MOSCOW - The president of Belarus ordered a halt to the transit of Russian natural gas to Europe on Tuesday, escalating an energy conflict with Moscow over unpaid debts that he said was turning into a "gas war."
The move came after Russia's state-owned gas giant Gazprom announced that it was doubling the cut in supplies to Belarus to 30 percent of normal volumes on Tuesday in an effort to collect about $200 million it says the country owes. The Belarussian president, Aleksandr G. Lukashenko, accused Gazprom in turn of failing to pay $260 million in fees to transport gas through Belarus's pipeline to Europe - roughly a fifth of Russia's westward exports - and ordered the flow halted.
"I have ordered my government to stop transit through Belarus as long as Gazprom does not pay for the transit," Mr. Lukashenko said in a meeting with Russia's foreign minister, Sergey V. Lavrov. "They have not paid one kopeck for a half a year."
Gazprom officials denied that, saying that the government of Belarus had been hindering payment of the transit fees to gain leverage in the dispute.
"Instead of looking for money to pay for the debt," Belarus "decided to cut off the Russian supplies," Sergei V. Kupriyanov, Gazprom's spokesman, said at a news conference. "This is not only our gas; this is our pipeline that belongs to Gazprom."
Marlene Holzner, a spokeswoman for the European Commission, said at a separate news conference that there was no indication that Belarus had in fact halted the flow of gas. Ms. Holzner had said that it was unlikely that Europe would be affected by any cutoffs because of low summertime energy demands.
Nevertheless, the conflict has raised further questions about Europe's reliance on Russian energy supplies. There have been other conflicts with Russia over energy in recent years, including Gazprom's pricing dispute last year with Belarus's southern neighbor, Ukraine, which led to a gas shutoff that left millions of European homes without heat.
The latest dispute erupted Monday when Russia said it was reducing gas deliveries to Belarus by 15 percent because of its unpaid debts, vowing to cut deliveries by as much as 85 percent.
On Tuesday, Mr. Kupriyanov assured Europe that gas flows would continue unhindered, saying that Ukraine had agreed to move additional supplies through its pipelines, which already carry most of Europe's Russian gas.
"We are sure that our European clients will get all the necessary amounts of volumes of gas according to our contract" regardless of Belarus's actions, he said.
Mr. Lukashenko, meanwhile, accused Russian officials of insulting the Belarussian people, saying that he had been forced to seek loans from "strangers" to satisfy Russian demands for immediate payment.
"The behavior of the Russian leadership is incomprehensible to me," Mr. Lukashenko said.
The conflict comes at a time of rising tensions between Russia and Belarus. Mr. Lukashenko, who in the past has readily fallen into line with Russian policies, has of late grown recalcitrant, refusing to go along with several Kremlin initiatives, including a strengthened and simplified trade relationship featuring a customs union with Russia and Kazakhstan.
Mr. Lukashenko has also provoked Moscow by harboring Kurmanbek S. Bakiyev, the former president of Kyrgyzstan, who was ousted after an uprising that Russia appeared to encourage.