+++ Greek debt crisis - live updates +++

All updates in Universal Coordinated Time (UTC)

23.25 This concludes our ticker for now. We've rounded up events in the run-down to the Greek default and we'll be covering the latest on the implications throughout Wednesday. So many questions remain to be answered. Can Greece now remain a part of the eurozone? Will Sunday's referendum, for Greeks to decide on the terms of the creditors' most recent bailout offer, go ahead as planned?

22:27 Spokesman for the IMF Gerry Rice says the Fund received a request to have the repayment of the debt extended, but said that it had not yet been ruled upon by the IMF's board. The request was set to be passed to the board "in due course," said Rice.

22:09 The IMF confirms that the debt due by Greece has not been paid. Failure to meet the payment means that the country officially falls into default. "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. The missed payment is the largest in the Fund's history.

22:00 Midnight deadline (CET) passes for Greece to make its 1.6-billion-euro ($1.8 billion) repayment to the IMF. It means that the country's international bailout formally expires and the country loses access to emergency funding.

20:50 The ratings agency Fitch has cut the country's credit rating further within the junk status category, from the CCC grading to CC-, which is one notch above the level where Fitch believes default would be inevitable. "The breakdown of the negotiations between the Greek government and its creditors has significantly increased the risk that Greece will not be able to honour its debt obligations in the coming months, including bonds held by the private sector," Fitch said in a statement.

19:08 The chairman of the Eurogroup, Jeroen Dijsselbloem, told Reuters news agency that Greece would have to change its stance toward its international creditors if its eurozone partners were to consider giving any more financial assistance. Speaking after an emergency teleconference of eurozone finance ministers, he said it was too late to extend Greece's current bailout program as requested by Athens, and that any new program might impose tougher conditions than the previous one. He also confirmed that Greece was set to default on a payment to the IMF due by midnight.

18:21 A Greek official confirms that the eurozone finance ministers' meeting has ended, and says it will continue on Wednesday morning. He spoke on condition of anonymity and gave no details.

18:14 After participating in a teleconference of eurozone finance ministers to debate a new proposal from Athens, Finnish Finance Minister Alexander Stubb wrote on Twitter that no short-term extension of Greece's bailout or debt haircut for the country was possible.

17:07 US President Barack Obama said the current situation in Greece should not be "a major shock" to the US economic system, but that officials had been monitoring events. He admitted, however, that the crisis could be painful for Greece and significantly affect European growth.

16:35 Europe's main indexes registered clear losses as hopes faded of a last-minute deal to prevent Greece defaulting on its payment to the International Monetary Fund due at the stroke of midnight. (We wonder whether they're accounting for the extra second.) Frankfurt's DAX 30 lost 1.25 percent, the CAC 40 in Paris sank 1.63, while Rome and Madrid fell by 0.48 and 0.78 percent respectively.

16:12 DW analysis of events so far from our correspondent Andrea Rönsberg in Brussels.

15.04 German Chancellor Angela Merkel said Germany would not consider the third bailout package proposed by the Greek government before the referendum in Greece on Sunday. "No new proposal can be discussed by Germany before a referendum," she said in comments reported by participants at a parliamentary party meeting of the CDU/CSU. Greek Prime Minister Alexis Tsipras has requested a two-year rescue deal, and a short extension to Greece's current bailout program to avoid a "technical default," with Athens due to make a 1.6 billion euro ($1.8 billion) payment to the IMF in just hours.

14:36 The eurozone's finance ministers - known as the Eurogroup - will hold a telephone conference to debate Greece's latest request for aid at 17:00 UTC, the group's head Jeroen Dijsselbloem said on his Twitter account.

14:30 US stocks rose in early trading amid speculation that Athens was mulling a last-minute deal to break a stalemate with its international creditors. The S & P 500 index and the Dow Jones industrial average both climbed 0.4 percent, while the Nasdaz composite went up 0.6 percent. This follows the US market's worst day of the year on Monday after talks between Greece and its creditors broke down.

14:15 German Chancellor Angela Merkel told lawmakers that she did not expect any new developments on Greece on Tuesday, as time was too short to allow necessary procedures, such as German parliamentary approval, to take place. In remarks reported by two participants at the meeting, she said it was important for the 18 other eurozone countries to stand together, adding that while compromise between partners was important, there should be no compromise for its own sake.

13:51 The office of Greek Prime Minister Alexis Tsipras says the government in Athens has proposed a two-year deal with Europe's bailout fund, the European Stability Mechanism. The deal would "fully cover its (Greece's) fiscal needs with the simultaneous restructuring of debt," according to the office. It also said that the government would seek "until the end" to find a way of remaining within the eurozone and remain at the negotiating table to this end. Concrete detail was not provided. The proposal came hours before Athens was set to default on a loan to the International Monetary Fund (IMF).

13:30 The German Confederation of Trade Unions (DGB) has called for a financial lifeline to be extended to Greece until after the referendum on Sunday, and for the 1.5 billion ($1.7 billion) dollar loan instalment due to the IMF on Tuesday to be postponed. DGB chief Reiner Hoffmann and the chairman of the Greek General Confederation of Greek Workers (GSEE) called on all parties in a joint statement to "avoid a Grexit with all possible means."

13:28 The mayor of Athens, Giorgios Kaminis, has called on Greek citizens to vote in favor of the economic reform program demanded by Greece's international creditors in Sunday's referendum, Greek television says. Kaminis said the referendum would polarize the population.

12:35 In a letter published in Britain's "Financial Times" newspaper, 19 top-flight economists, including US Nobel Prize winner Joseph Stiglitz and French economist Thomas Picketty, call on European leaders to enable Greece to repay the 1.6 billion euros ($1.8 billion) it owes to the IMF. The letter demands for "a fresh start" for Greece, pointing out that the IMF's own researchers had discredited the austerity policy demanded of Athens, and that the new Greek government had committed to carry out wide-ranging reforms if given the chance to do so.

11:45 German Chancellor Angela Merkel tells reporters in Berlin that she sees no chance for a last-minute deal with Greece before the end of this Tuesday. Merkel says "the program will expire at midnight Central European Time" and that she has seen no indications of a breakthrough with Greece.

11:17 Finance Minister Yanis Varoufakis confirms that Greece will not make its payment due by the end of Tuesday to the International Monetary Fund. When asked while walking into the Finance Ministry whether Greece would pay the 1.6 billion euros due to the IMF, Varoufakis replies "no."

10:43 European stock markets trim losses amid speculation of a possible last-minute deal pull Greece back from the brink of default.

09:37 The Greek daily paper "Kathimerini" reports that Prime Minister Tsipras is considering the offer from the European Commission.

07:07 The Reuters news agency reports that European Commission President Jean-Claude Juncker has made a last-ditch offer to Greek Prime Minister Alexis Tsipras to save the country from default, expected by the end of Tuesday when an International Monetary Fund repayment worth 1.6 billion euros ($1.8 billion) comes due.

To unlock the funds, not only would Tsipras have to accept the creditors' conditions - something that he has so far refused to do - but he would also have to reverse his recommendation for next Sunday's referendum on the bailout package, recommending that Greeks accept, rather than reject the financial aid. The final stipulation is that he responds positively in time for Juncker to convene a meeting of finance ministers before the end of Tuesday.

tj, pfd, rc/msh (Reuters, AP, AFP, dpa)