The International Monetary Fund has warned it may not have enough money to bail out larger eurozone countries if the debt crisis afflicting Greece were to spread to other European Union states.
IMF chief Christine Lagarde says the global lender can meet its current obligations but this could change if the crisis worsens.
The comments come after a series of meetings in Washington to discuss the situation, including one between Ms Lagarde and Greek Finance Minister Evangelos Venizelos.
Speaking after that meeting, Mr Venizelos said Greece would do "whatever it takes" to reduce its deficit.
Publicly, world leaders have said there is "no plan" for a Greek default but the BBC reports there are indication leaders are working on a plan to allow Greece to default on its debts and remain in the euro.
This is reported to involved a 50% write down in Greece's public sector borrowings and quadrupling to 2 trillion euros the EU's main bailout fund, the European Financial Stability Facility.
The deal is also said to involve putting in place arrangements to allow the European Central Bank (ECB) to lend alongside the fund, and a strengthening of the big Eurozone banks that are perceived to have too little capital to absorb losses.
Antonio Borges, the head of the IMF's European department, has called for the ECB to play a much bigger role in fighting the crisis, saying it is the only institution powerful enough to keep the eurozone's debt crisis from further damaging the global economy.
The BBC reports that turning the outline being discussed into a practical plan will be immensely difficult, but the failure to do so risks turning anaemic economic growth into a recession or worse.
The crisis has already caused stockmarkets to slump and oil to fall in price, along with prices for nickel, aluminium and copper.
Greece awaits auditors' visit
Greece is preparing for the return of European and IMF officials for a fiscal audit that will decide if it can escape default in October.
EU and IMF officials are to return to Athens this week to monitor the country's progress on its deficit reduction plans.
The country is still receiving money from an initial rescue package which was agreed in May last year.
But the BBC reports it will not receive the next tranche if the inspectors rule that it is not keeping up with its spending cut targets.
Without the latest instalment of the loan, Greece will not be able to meet its debt payments by the middle of October.
'Sticking plaster' approach not enough
Investors are increasingly sceptical that Greece can avoid a default and that the crisis can be prevented from rolling to other nations.
British investment firm Hargreaves Lansdown says the IMF and the EU have so far used a sticking plaster approach to the European debt crisis.
Head of research Mark Dampier told Morning Report that fund holders need to commit up to $NZ4 trillion to stop the crisis in its tracks.