Greece's debt dilemma explained in 90 seconds
Greece is scheduled to pay 300m euros (£216m) to the IMF on Friday, with a further 1.3bn euros due by the end of June.
On Thursday the Greek government asked the IMF if it could pay all the money due in one lump sum at the end of the month.
This is set against the context of Greece's ongoing negotiations with European finance ministers about the extent of reforms it needs to undertake, as part of its bailout deal.
This video sets out the basic framework of Greece's debt crisis, and speculates on what might lie ahead for Greece.
05 Jun 2015