The International Monetary Fund said Monday it was "monitoring the situation" in Ukraine after disputed pro-Russia separatist votes in the east of the country.

In April, the IMF approved a $17 billion aid package for Ukraine, but warned it may need to be recalibrated if Kiev loses control of the highly industrialized east.

According to the global crisis lender, the eastern provinces of Donetsk, Lugansk and Kharkiv account for 21.5 percent of the country's economic output and 30 percent of industrial production.

Separatists held controversial referendums in Donetsk and Lugansk on Sunday and said the votes were victories for independence.

The IMF, which has already disbursed $3.2 billion of the aid to Kiev, has not indicated what it would do if the country breaks up.

The IMF releases loan installments on condition national authorities make sufficient progress in economic reforms and other measures required by the aid program.

The next scheduled program review for Kiev is in July.