Under the program, Ukraine has already received almost $10 billion this year to shore up its finances crippled by separatist conflict and years of economic mismanagement and corruption.
However the disbursement of the next $1.7 billion tranche has been delayed as the IMF said the government and parliament, which are in disagreement over proposed tax reforms, needed more time to sort out fiscal polices for 2016.
"The mission will continue policy discussions with the Ukrainian authorities in the context of the second review of the Fund-supported economic reform program," Vacher said.
A key requirement under the IMF program is cutting the 2016 budget deficit to 3.7 percent of gross domestic product from the current level of 4.1 percent.
Last week Prime Minister Arsenii Yatseniuk said Ukraine risked losing the support of its Western backers if the squabble over the size of tax cuts delays or derails promised reforms.
Apart from the IMF loans, Ukraine also hopes to receive a further $2.7 billion this year from other lenders, including a third $1-billion loan guarantee from the United States.
U.S. Treasury Secretary Jack Lew will visit Kyiv on Friday and assess Ukraine's progress in its reform drive, Yatseniuk said in a government meeting on Wednesday.