Ukraine's finance minister, Viktor Pynzenyk, has stepped down, citing political pressure and feuding within the government.

In a letter, the minister described himself as a hostage to politics and said he could not abandon the principles of a balanced budget with a minimum deficit. He said under such conditions he sees no point in remaining in his post.

Wednesday Ukrainian Prime Minister Yulia Tymoshenko appealed to the world's seven leading industrial countries for a $5 billion loan to help her country cover a budget deficit.

An International Monetary Fund mission left Ukraine without making a decision on granting the country the second installment of a $16 billion loan negotiated last year.

In Washington, a fund spokesman, David Hawley, said talks on the issue are continuing, but stressed the importance of instituting reforms.

The loan agreement had called for cuts in government spending and increased energy tariffs.  The IMF asked Ukraine to tighten its monetary and fiscal policy, in order to achieve a balanced budget this year.

The program also asks Ukraine to adopt a flexible exchange rate, allowing markets to set currency values.

Some information for this report was provided by AFP and Reuters.