Ukraine will settle its Russian gas bills today ahead of a deadline, officials said and one called for an apology from Moscow for comments that cast doubt on its ability to pay, according to Reuters. Russia has warned gas supplies to Europe could stop within weeks if Ukraine does not pay for gas placed in underground storage that is needed to keep pressure in pipelines to ensure smooth transit. It cut supplies to Ukraine and later to Europe in January during a three-week stand-off over state energy firm Naftogaz's debts and the price of gas. "We will pay during the day," Naftogaz spokesman Valentyn Zemlyansky told Reuters. Yushchenko said in a statement: "We will not allow a gas crisis to happen. Ukrainian and foreign consumers will get their gas." His energy envoy, Bohdan Sokolovsky, was cited by Interfax Ukraine as saying Russia should apologise. "We expect, after payment is completed, an apology to follow from the Russian side, considering these incorrect and humiliating statements ... concerning the ability of Ukraine to pay for gas," he said. Gazprom declined to comment but Russian President Dmitry Medvedev said there was no reason for Ukraine to take offence. "Our Ukrainian partners took offence because Russia suggested they were unable or unwilling to make payment," Medvedev said at an economic forum in St Petersburg. "Why should they take offence? Let them pay the money and everything will be all right." Ukraine needs to pay $657 million by June 7 for 2.4 billion cubic metres of gas, including $500 million for gas placed in underground storage. A confirmation of payment was expected by midnight (2100 GMT). Yushchenko, locked in a protracted power struggle with Prime Minister Yulia Tymoshenko, has cast doubt over Naftogaz's finances. He said the company had $7.4 billion worth of debts, while this year's revenues were expected to be $7.8 billion. Tymoshenko and her government, which is responsible for Naftogaz, say the company's finances are stable. Ukraine expects to import 7 billion cubic metres (bcm) of gas in the second quarter, 9.5 bcm in the third quarter and 14 bcm in the final quarter, according to government documents made public on Friday. According to an agreement with Russia struck in January after the stand-off, Ukraine pays for gas this year at a 20 percent discount to market prices. This means it expects gas prices to fall sharply towards the end of the year. It sees the price for Russian gas at $160 per 1,000 cubic metres in the final quarter when it wants to import twice the volume it expects to buy in this quarter. It paid $360 per 1,000 cubic metres in the first quarter.