The head of the International Monetary Fund, Christine Lagarde, has warned Ukraine it would be unable to keep supporting it financially if the country doesn't step up its reforms efforts.

Ukraine relies on funding from the IMF and international donors as it battles deep economic problems, in large part resulting from the conflict in the country's east.

Lagarde says in a statement "it is hard to see how the IMF-supported program can continue and be successful" without a crackdown on corruption and a new push for governance reforms.

Ukraine is still waiting for the IMF to provide an installment of funding that has been delayed since October amid disputes over the budget.

Last week, Ukrainian Economy Minister Aivaras Abromavicius resigned, saying his reform efforts had been blocked by government colleagues.