Ukraine has reached a deal with the International Monetary Fund and other agencies for payment of Russian gas bills.
European Commission chief Jose Manuel Barroso says it should provide the stability needed to significantly reduce the risk of a further gas crisis between Ukraine and Russia.
A dispute between Moscow and Kiev in January meant gas supplies were cut across eastern and western Europe.
Russia provides about a quarter of the gas consumed in the EU - and 80% of that is piped through Ukraine.
The commission says the deal will allow Kiev to restock its reservoirs.
The International Monetary Fund will release a third tranche worth $US3.3 billion from a credit line of $US16.4 billion over two years.
The World Bank and the European Bank for Reconstruction & Development will also provide 570 million in October.
Ukraine is due to pay a gas bill of about $US640 million on 7 August.