Russia's state-controlled gas monopoly said a deal to monitor gas exports via Ukraine would be signed today, allowing for the resumption of supplies to Europe cut off by Moscow's price row with Kiev.
"We expect that in the course of today the protocol on the creation of an international independent mechanism to guarantee the transit of Russian gas through Ukraine will be signed," Interfax quoted Gazprom CEO Alexei Miller as saying.
"And immediately after that we will renew (gas) deliveries."
The European Commission said a gas monitoring team had already started work in Kiev, but Commission President Jose Manuel Barroso said it would take time to resume shipments, cut off for several days as Europe suffered bitter winter weather.
Miller was speaking after meeting Russian President Dmitry Medvedev who said he wanted to see gas flowing to Europe "as quickly as possible." Medvedev added that a deal must be signed before shipments resume.
Czech Prime Minister Mirek Topolanek, whose country holds the European Union presidency, will travel to Ukraine on Friday to finalise agreement on the monitoring, a Czech source said.
In a sign that obstacles remained to a deal, Ukraine's state energy company Naftogaz said Russia had not given Ukrainian monitors access to gas-pumping stations on Russian territory.
Russian officials have said even once the monitors are in place, it could take many hours and possibly days before Russian gas shipped via Ukraine starts reaching Europe again.
Resuming the flows involves building up pressure in the pipeline network, and the large distances involved mean that, once moving, the gas will take time to reach customers.
The gas is likely to be delivered only to Europe, not Ukraine itself, since Moscow and Kiev have yet to agree a price for the gas, subsidised since Soviet times. Russia has repeatedly said Ukraine must now pay the going market rate.
But the presence of monitoring missions at points along the transit routes for Russian gas will reassure Moscow that the gas it is pumping across Ukraine is not being siphoned off by Kiev.
Moscow cited this allegation, denied by Ukraine, as its reason for shutting off gas through its ex-Soviet neighbour earlier this week.
Reuters