President Vladimir Putin on Wednesday ordered his government to sue Ukraine if the ex-Soviet republic defaults on its $3 billion (about 2.7 billion euros) debt to Russia. "Go ahead, take it to court," Putin told Finance Minister Anton Siluanov at a government meeting while discussing the loan given to former Kremlin-backed president Viktor Yanukovych in 2013, which must be repaid this month. The dispute has been hampering the International Monetary Fund's $17.5-billion rescue plan for Ukraine, which restricted Kiev's ability to restructure billions of dollars in debt, including some held by Moscow.