Russian Prime Minister Vladimir Putin gave critical support to hopes for stable natural gas deliveries to Europe, saying he found working with Ukrainian Prime Minister Yulia Tymoshenko on energy "comfortable," according to Friday news reports quoted by dpa. "She (Tymoshenko) is a tough negotiator," Putin said, as a smiling Tymoshenko looked on. "But we have always been able to agree, and, in spite of all difficulties, we have managed to keep to all our commitments." Putin made the approving comments at a televised press conference Thursday evening in the Ukrainian city of Yalta. Putin and Tymoshenko met in the Black Sea port for talks on energy and other bialateral issues. A December 2008 energy contract row between the two countries" governments, with Putin and Tymoshenko at their respective heads, ended in a five-day halt of all Russian natural gas shipments to Europe via Ukrainian pipelines in January 2009, spiking retail prices as far away as Spain. Russia"s main complaint during that conflict, that Ukraine allegedly was siphoning Russian gas destined for Europe and not paying for it, was now a non-issue now, Putin said, speaking at a press conference. "Ukraine is fufilling all of its obligations," he said. "We hope to meet the New Year without any problems." Tymoshenko made clear she also felt energy disputes with the Kremlin were now in the past, and that continued Russian natural gas supplies to Europe through Ukraine were assured. "We (Ukraine) fully and thoroughly will fulfill our obligations on gas transit," she said. "We have always met our responsibilities." Representatives of the two countries" state-owned natural gas companies on Thursday signed a contract setting out planned volumes of Russian natural gas shipments to Ukraine and Europe for 2010. Talks in Yalta on Friday between members of Putin"s and Tymoshenko"s entourage would, aside from energy, focus on Russo- Ukrainian cooperation in aerospace and nuclear energy technologies, and trade relations, according to a Korrespondent web magazine report. Putin was scheduled to particpate in a meeting of CIS government heads in Yalta later on Friday before returning to Moscow, according to officials at Ukraine"s Foreign Ministry.