KIEV, Jan. 12 - The Ukrainian economy has lost from $12 billion to $15 billion since the gas contracts were signed with Russia in 2009, Ukrainian presidential chief-of-staff Serhiy Liovochkin told journalists in Kiev on Thursday.

"This year we will "mark" the third anniversary of the signing of these gas contracts in 2009. If we tentatively calculate the losses caused to the Ukrainian state, meaning each Ukrainian citizen, since then, this figure will stand at approximately $12 billion-$15 billion," he said, describing it as "cautious estimates.”