Talks between Ukraine and Russia on a deal for natural gas deliveries are at a dead end, a senior Ukrainian official said Saturday evening, according to dpa. Negotiations between representatives from Kiev and the Kremlin on a contract for selling Russian gas to Ukraine and onward to European Union consumers are stalled and require intervention by national leaders to go forward, said Oleh Dubina, chairman of the Ukrainian natural gas monopoly Naftogaz Ukrainy. Dubina made the comments to Kiev reporters after returning from Moscow talks with representatives from the Russian natural gas monopoly Gazprom. The Ukrainian energy official did not make clear what issues still divided the two sides. The price to be paid by Ukraine for Russian natural gas, and the price to be paid by Russia for shipping its gas through Ukraine's pipeline network to Europe, were reportedly the most contentious issues. Failure by Gazprom and Naftogaz Ukrainy officials to negotiate new gas delivery terms for 2009, before the end of 2008, was the main cause of Russia's current embargo of gas deliveries to Ukraine and further downstream EU consumers. The EU on Friday and Saturday put forward a plan to place EU observers at points along the Ukrainian natural gas transportation network, to provide an independent accounting of Russian gas volumes sent to Europe.