Ukrainian Prime Minister Arseny Yatseniuk said in Kiev that the EU had agreed to serve as guarantor for Kiev in holding Russia to an agreement, notably on the price Ukraine would pay.
Yatseniuk, in figures later confirmed by Moscow, said Ukraine would pay $378 per 1,000 cubic metres to the end of 2014 and $365 in the first quarter of 2015.
He said Kiev was ready to pay off debts for gas immediately after any deal was signed.
A total of $1.45 billion would be paid immediately and a further $1.65 billion paid by the end of the year, he said.
Read MoreUkraine-Russia gas talks could leave EU in the cold
Russian Energy Minister Alexander Novak insisted that Ukraine would still have to pay up front for new deliveries to see its 45 million people through winter. Moscow expects some $1.6 billion for gas to be supplied.
Some critics of Russia question whether its motivation is financial or whether prolonging the wrangling with ex-Soviet Ukraine and its Western allies suits Moscow's diplomatic agenda.
Ukraine is in discussions with existing creditors the EU and the IMF.
The gas cut-off has had little impact for months. But pressure is mounting for a deal as temperatures start to drop below freezing.
Read MoreFears over gas supply as Russia-Ukraine talks fail
European Energy Commissioner Guenther Oettinger, who has been mediating, also leaves office on Friday, making way for a new European Commission.
"We can say to the citizens of Europe that we can guarantee security of supply over the winter," he said of what he called the $4.6-billion deal to supply Russian natural gas to Ukraine.
EU member states west of Ukraine would also, he said, have stable supplies, passing through Ukrainian pipelines, while Russia would gain the benefit of payment for its energy.
The two sides came close to an agreement in September, but last week differences were wide.