HELSINKI (AFP) - A top European Central Bank official said Saturday the institution cannot keep lending money to Greece unless the heavily indebted nation extends its bailout programme before a February deadline.

The remarks from Bank of Finland Governor Erkki Liikanen - who sits on the ECB's governing council - come one month before the bailout programme agreed upon by Greece with Europe and the International Monetary Fund is set to expire.

"Greece's programme extension will expire at the end of February so some kind of solution must be found, otherwise we can't continue lending," Liikanen told Finnish public broadcaster Yle.

Syriza - the radical-left coalition that won Greek elections last week - has pledged to renegotiate the terms of the country's bailout.

"Significant debt restructuring has been carried out with private investors. The ECB cannot fund a state directly, which is what it would mean in this case," Liikanen said.

Following Syriza's victory Finnish Prime Minister Alexander Stubb said he opposed debt relief but would consider extending Greece's loan repayment period.

"We're sticking to what we've agreed on... but we can extend the loan period," Stubb told reports in Helsinki.

Finland took a tougher stance than other eurozone states in 2011 when the second Greek bailout package was agreed, demanding collateral for its portion of a programme worth €159 billion (S$243 billion).