Russia has filed a lawsuit against Ukraine after Kyiv failed to repay a $3 billion Eurobond.
Russian Finance Minister Anton Siluanov said the lawsuit was filed on February 17 at the High Court in London.
"This lawsuit was filed after repeated unsuccessful attempts to engage Ukraine in constructive dialogue about restructuring the debt and to admit the fact that Russia-owned Eurobonds are an official loan," Siluanov said in comments quoted by Russian media.
The Eurobond was issued by the government of former President Viktor Yanukovych in late 2013 and bought by Russia in its entirety.
The bond was issued just two months before Yanukovych fled Ukraine amid street protests triggered by his seeking to halt Ukraine's swing toward European integration in favor of closer economic ties with Russia.
Ukraine, which has separately reached an agreement with private creditors to restructure its sovereign and sovereign-guaranteed debt, insists the Eurobond is a commercial debt and that it cannot offer Russia a better deal than other creditors.