MOSCOW, Dec. 7 - Russia has no choice but to sue Ukraine if the borrower fails to fully honor its obligations on December 20, the Russian Finance Ministry said in a statement released on Saturday.

"Despite the absence of Ukraine's official request for the Russian government, concerning the restructuring of the $3 billion sovereign debt, Russia itself proposed a three-year deferral (2016-2018) of the repayment of the Ukrainian debt under the guarantee of the United States, the European Union or a first-class international financial institution," the ministry said.