Russia says differences with Ukraine on reducing the price of Russian gas have been narrowed after talks in the Black Sea resort of Sochi.Russian presidential spokesman Dmitry Peskov said the talks would continue at a later date.
Ukraine's President Viktor Yanukovych and his Russian counterpart Vladimir Putin had been expected to debate Kiev joining a Moscow-led customs union.
But both Russia and Ukraine said the issue had not been discussed.
Street protests have continued in the Ukrainian capital Kiev, where a new call was made for the resignation of the government.
'Gap being bridged'
Last month Mr Yanukovych shelved a partnership deal with the EU, triggering angry protests in Ukraine's capital Kiev.
Russia was unhappy with the deal and Mr Putin has been urging Ukraine to join a Russian customs union with Belarus and Kazakhstan.
The two neighbours have also been trying to resolve a long-running dispute over energy supplies.
Ukraine depends on imports of Russian gas, but the supplier, Gazprom, has recently complained that Kiev had fallen behind in payments.
Disputes over supplies to Ukraine before 2009 saw Gazprom temporarily cutting off supplies.
Pipelines passing through Ukraine also pump Russian gas to many EU member states.
Mr Peskov told Interfax news agency that "great attention [had] been devoted to the co-operation in the energy sphere".
"Both sides narrowed the gap between their positions as a result of the discussion," he said. "However, no final agreement has been reached."
The issue of Ukraine joining the customs union was not discussed during the meeting in Sochi, according to both Mr Peskov and a statement from Mr Yanukovych's office.
Correspondents had earlier speculated that an agreement on Ukraine joining the customs union might be reached in return for reduced energy prices.
Three conditions
Many Ukrainians were furious that Mr Yanukovych refused to sign the association agreement with the EU, which had followed years of negotiations.
On Saturday, several thousand supporters of the EU deal braved snow and swirling winds as they maintained control of Kiev's Independence Square for the seventh successive day.
Protest organisers say they expect up to 300,000 people to turn out on Sunday for fresh demonstrations.
Protest leaders have set out three conditions for any negotiations with President Yanukovych: the resignation of his government, the release of protesters arrested during clashes in Kiev and the punishment of those responsible for beating demonstrators.
