The two leaders are scheduled to meet in the Ukrainian leader's industrial power base of Donetsk for a summit on regional cooperation but energy is expected to top the agenda. Medvedev, who will be accompanied to the talks by Alexei Miller, chief executive of gas giant Gazprom, has been dangling the offer of cheaper gas in exchange for Ukraine's promise of tighter cooperation with Russia. Kiev, which has made no secret of its European Union integration aspirations, has until now steadfastly resisted Russia's pressure. The talks follow a landmark three-way meeting between the two leaders and Russian Prime Minister Vladimir Putin at a hunting lodge outside Moscow last month and come as Ukraine reels from a diplomatic crisis in ties with Brussels. The unprecedented crisis has been triggered by the jailing of ex-prime minister Yulia Tymoshenko which could make Ukraine more vulnerable to the Kremlin's advances, analysts say. Russia has repeatedly said it could agree to sell Kiev gas at lower prices if Ukraine cedes control of its prized Soviet-era pipeline grid. Ukraine has repeatedly resisted the pressure. A Ukrainian source said last week that Miller and Ukrainian Energy Minister Yury Boiko might meet in Donetsk again Thursday when the city hosts a football match between Ukraine's Shakhtar Donetsk and Russian club Zenit St Petersburg. A Gazprom official could not confirm that plan Monday. Russian and Ukrainian officials were scheduled to sign several cooperation agreements but no commercial deals were expected. On Thursday, Yanukovych had been scheduled to travel to Brussels for talks with EU officials but following the jailing of Yanukovych's rival and opposition leader Tymoshenko, that plan is now in limbo. The EU warned that the verdict risked having "profound implications", only to see Ukraine launch a new probe against the Orange Revolution leader over suspected embezzlement. Ukraine is hoping to sign off on an association agreement with the European Union at a December summit in Kiev, a first step towards membership. A European diplomat, speaking to AFP on condition of anonymity, suggested that plans for both Yanukovych's Brussels visit and the summit could be revisited, however. "The European Union does not want to let Russia take advantage of a cool-down in its ties with Ukraine," Fyodor Lukyanov, editor of Russia in Global Affairs magazine, told AFP. "Russia understands this and will play its own game." Ukraine sentenced Tymoshenko for signing a gas contract with Russia in 2009, claiming it is forced to overpay by up to $8 billion.