Greece has missed the deadline for a €1.6bn (£1.1bn) payment to the International Monetary Fund (IMF), hours after eurozone ministers refused to extend its bailout.
But the ministers say they will discuss a last-minute request from Greece for a new two-year bailout on Wednesday.
Greece is the first advanced country to fail to repay a loan to the IMF and is now formally in arrears.
There are fears that this could put Greece at risk of leaving the euro.
The IMF confirmed that Greece had failed to make the payment, shortly after 22:00 GMT on Tuesday.
“We have informed our Executive Board that Greece is now in arrears and can only receive IMF financing once the arrears are cleared,” said IMF spokesman Gerry Rice.
Mr Rice confirmed the IMF had received a request from Greece to extend the payment deadline, which he said would go to the board “in due course”.
With the eurozone bailout expired, Greece no longer has access to billions of euros in funds and could not meet its IMF repayment.
The European Central Bank (ECB) has also frozen its liquidity lifeline to Greek banks. Meanwhile, ratings agencies have further downgraded the country’s debt.