Ukraine has settled its bill for Russian gas supplies in May after Russia cast doubts on its ability to pay.
Ukraine needed to pay $US657 million by Sunday for 2.4 billion cubic metres of gas, including $US500 million for gas placed in underground storage.
Russia had warned that gas supplies to Europe could stop within weeks if Ukraine did not pay for gas in underground storage. This is needed to keep pressure in pipelines to ensure smooth transit.
Moscow cut supplies to Ukraine, and later to Europe, in January during a three-week stand-off over Naftogaz's debts and the price of gas.
Europe gets a quarter of its gas supplies from Russia, most of it via Ukraine.
State energy company Naftogaz said on Friday the amount had been paid.
According to government documents made public on Friday, Ukraine expects to import 7 billion cubic metres of gas in the second quarter, 9.5 bcm in the third quarter and 14 bcm in the final quarter.