"Ukraine risks a return to the pattern of failed economic policies that has plagued its recent history," Lagarde said in a statement.
Expressing concern about Kiev’s slow progress in government reform, Lagarde urged its leadership to act "now to put the country back on a promising path."
"Without a substantial new effort to invigorate governance reforms and fight corruption, it is hard to see how the IMF-supported program can continue and be successful," she stressed.
The IMF approved a four-year $17.5 billion assistance package to Ukraine last March in exchange for reforms including anti-corruption policies.
Kiev has received two payments under the economic support program. On January 21, Poroshenko announced the country expected to receive the next tranche from the fund in February.
Ukraine's Economic Development and Trade Minister Aivaras Abromavicius announced his resignation last week, a little over a year after assuming office, saying he was unable to work effectively. Lagarde suggested Abromavicius’ claims about corruption could indicate a failure of reforms.
