Russian President Dmitry Medvedev (L) speaks with President of the European Commission Jose Manuel Barroso (R) at the EU-Russia summit in Stockholm on November 18, 2009. The summit was dominated by energy issues, as Europe hopes to avoid an interruption of Russian natural gas supplies via Ukraine this winter. (Vladimir Rodionov/AFP/Getty Images)
Even before they met, the Kremlin snubbed Ukrainian President Viktor Yushchenko who had called for a revision of a gas agreement brokered by the two leaders early this year and it accused Kiev of trying to blackmail Russia and Europe over energy supplies.
The deal last January ended a conflict over gas pricing which led to Russian gas flows to Europe via Ukraine being halted for two weeks in mid-winter.
Millions in southern Europe were left without heating.
But relations between Russia and the former Soviet republic have slid further in the run-up to a presidential election on Jan. 17, and the outcome of the talks, in Yalta, southern Ukraine, was difficult to read.
The gas deal has become mired in infighting in Ukraine between Tymoshenko and Yushchenko, her political rival.
Though Ukraine has so far settled all its bills on time, Tymoshenko has conceded that, given the dire state of the economy, meeting the monthly payments for gas is a struggle.
She says however that the 10-year supply contract agreed with Russia does not have to be revised and provides for stable supplies of gas in 2010.
Putin, though, has raised the temperature around the talks, due to take place later on Thursday, with a warning that Russia will cut gas deliveries again if Ukraine stops paying on time or siphons off transit gas.
A Putin aide said on Wednesday that the Russian leader, who is taking with him a heavyweight team including Gazprom's CEO Alexei Miller, was "pressing all the pedals" in an attempt to sort out gas problems with Ukraine.
Russian supplies across Ukraine provides Europe with a fifth of its gas and earlier this week an anxious EU agreed with Russia an "early warning" mechanism to shield Europe from potential energy supply cuts in the event of further cuts.
Just hours before talks were due to start, Yushchenko, who has constantly sniped at Tymoshenko for accepting last January's deal, appealed to Russian President Dmitry Medvedev to revise the agreement which he said was too onerous for the Ukrainian economy.
He believes the price accepted for Russian gas was too high while transit fees coming to Ukraine were pitched too low.
In an open letter to the Kremlin chief, published on his website, Yushchenko said: "Keeping the contracts unchanged ... will create potential threats specifically to the reliability of supplies of gas to Ukraine and its transit to other European states."
But Kremlin aide Sergei Prikhodko, speaking to journalists in Moscow, poured scorn on Yushchenko's plea.
Ridiculing Yushchenko and Tymoshenko for constantly contradicting each other, he said: "We are categorically against energy security in Europe becoming dependent on the personal ambitions of Ukrainian politicians.
"The attempt to intimidate Russia and Europe with forecasts of a crisis in the transit of gas -- this already looks something like political blackmail," he said.
Prikhodko said gas relations between the two countries had a solid juridical base. "Of course these are not set in stone and we are always open to negotiations with our Ukrainian partners," he said.
Medvedev last summer publicly wrote off relations with the pro-western Yushchenko, accusing him of pursuing anti-Russian policies.
