The NBU's independence is at the centre of the IMF's program for Ukraine / Photo from flickr.com/freeimage4life

The International Monetary Fund (IMF) urged Ukraine on Thursday to maintain the independence of the central bank after Governor Yakiv Smolii unexpectedly resigned, citing "systematic political pressure."

"Under his leadership, Ukraine has made important strides in achieving price stability, amply demonstrating that an independent central bank is a key element of modern macroeconomic policymaking," an IMF spokesman said in a statement, according to Reuters.

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"That is why the independence of the NBU is at the centre of Ukraine's Fund-supported programme, and why it must be maintained under his successor."

Smolii's resignation, if accepted by President Volodymyr Zelensky, risks derailing a US$5 billion deal agreed with the IMF last month to fight an economic slump caused by the COVID-19 pandemic.

Despite reassurances from Zelensky's office on Wednesday, Smolii's resignation sent sovereign bonds down by more than two cents and the local hryvnia currency down to its lowest level since April against the dollar, Reuters said.