KIEV, Feb. 10 - President Viktor Yushchenko on Tuesday said Prime Minister Yulia Tymoshenko had abused her authority while signing the natural gas deal with Russia on Jan. 19.

Yushchenko, who spoke at a meeting of the National Security and Defense Council, the country’s top security body, criticized the deal as unfair for Ukraine.

“According to the prime minister, we have received a big victory in gas talks. This victory is so big that we don’t know what to do with it,” Yushchenko said in remarks broadcast by the state television on Tuesday.