The United States urged Russia on Sunday to resume pumping gas to Europe through Ukraine at once after finally agreeing a price for 2009 as negotiators worked on a detailed Russian-Ukrainian agreement to be signed on Monday, according to Reuters. The prime ministers of Ukraine and Russia said they had agreed an outline deal that would restore gas supplies to Europe "very soon", but the European Union said it wanted to see gas flowing before applauding. The failure of the two ex-Soviet neighbours to agree a price for Russian gas has enraged the EU by leaving large parts of Europe without gas in the middle of winter, and has hurt Russia's and Ukraine's credibility as gas supplier and transit route respectively. "Gas transit, the Ukrainian side assured us, will be restored very soon," Russian Prime Minister Vladimir Putin said after talks that lasted into the early hours of Sunday. The United States urged Russian gas firm Gazprom to restart gas flows "immediately" in a statement from its embassy in Kiev. A spokeswoman for Ukrainian Prime Minister Yulia Tymoshenko said she would fly back to Moscow on Monday for a signing if the respective gas companies, Gazprom and Naftogaz of Ukraine, had finalised details of the deal by then. The firms spent the day working out details of the accord, many of which were not made public. Foreign journalists were barred from Gazprom's Moscow headquarters. Czech Industry Minister Martin Riman, speaking for the EU, said: "We remain realistic. Over the past few days we have seen several similarly hopeful moments. The only thing that counts for the EU is the resumption of gas supplies. For the time being it is not clear when this resumption takes place." After a bruising dispute that began on Jan. 1, analysts said there were few winners. "We will see that Europe is going to review all its energy policies pretty deeply," said Ronald Smith, chief strategist at Alfa Bank in Moscow. Full details of the new agreement were not given. Putin said Moscow had agreed to give Ukraine a 20 percent discount from the price European consumers pay, on condition Kiev froze tariffs for Russian gas transit to Europe across Ukraine in 2009 at last year's level. "We also agreed that, starting Jan. 1, 2010, we will fully move to gas prices and transit tariffs in line with European levels, without any reductions and discounts," Putin said. However, it was not clear which European market prices would be applied and what formulas would be used to determine them. Underlining Putin's dominance in Russian government, President Dmitry Medvedev did not attend the negotiations with Tymoshenko, and was not present when the deal was announced. Ukraine and Russia agreed not to use intermediaries in their gas trade, a Russian government source said. Previous deals have been complicated by the use of the Swiss-based intermediary Rosukrenergo, an opaque 50/50 joint venture between Gazprom and two Ukrainian businessmen. While Putin had full authority to seal an agreement, it remained unclear whether Tymoshenko's domestic political rival, President Viktor Yushchenko, would respect the deal. In Kiev, a source at Yushchenko's office said: "We are all waiting to see the agreement. Until the agreement is in the president's hands, he cannot make any comment on it."