KIEV — Ukrainian Prime Minister Yulia Tymoshenko said Wednesday that an agreement struck with Moscow in January guaranteed gas transit in 2010, but the Russian side said gas would be in the forefront in talks Thursday.

Tymoshenko spoke on the eve of talks with President Vladimir Putin, which analysts will monitor closely for signs of whether there could be another end-of-year dispute affecting supplies of Russian gas through Ukraine to Europe.

“I want to disappoint all those who constantly are weighing up gas conflicts … gas issues will not be discussed,” she said.

But Moscow quickly made clear that the gas issue would indeed be at the center of Thursday’s talks. “The situation in the gas sphere will be discussed thoroughly and in detail,” Putin’s deputy chief of staff, Yury Ushakov, told reporters in Moscow.

“Every seventh day of the month [when Ukraine’s payment for gas is due] a situation resembling a deadlock arises. This is a concern for the prime minister,” Ushakov said. “He is dealing with this issue, he is pressing all the pedals.”

Tymoshenko, under pressure from President Viktor Yushchenko, whom she is running against in a presidential election Jan. 17, said a gas agreement with Putin that ended the dispute last January was a good one and did not have to be revised.

Pressed by journalists, Tymoshenko said, “No new agreement exists. It is not needed.”

Asked about prospects for gas supplies to Europe across Ukraine in 2010, she said, “There is an absolute guarantee of stability.”

Putin raised the temperature around the talks in Yalta, southern Ukraine, when he said Nov. 11 that Russia would cut gas deliveries again if Ukraine stopped paying on time or siphoned off gas crossing its territory.

Russia is sending a large delegation to Yalta, including Deputy Prime Minister Igor Sechin, responsible for energy, Finance Minister Alexei Kudrin, and gas firm Gazprom’s CEO Alexei Miller.

Questions of whether Ukraine can meet monthly payments for gas have persisted because of the dire state of Ukraine’s economy. Even Tymoshenko has conceded that meeting the monthly bill is not easy.

A Yushchenko aide said Wednesday that gas transit had been assured this year only because of heavy borrowing by Naftogaz Ukrainy, the state energy company, but next year there would be a problem buying gas for storage, which is needed to support transit.

Ukraine had accepted “conditions of bondage,” Bohdan Sokolovsky, presidential energy envoy, told journalists, saying the situation in the gas sector was critical.