Talks over a gas pricing dispute between Ukraine and Russia have ended without an agreement, according to a source close to the negotiations.
The Ukrainian government has a deadline of 10.00 GMT tomorrow to pay its $1.95 billion debt.
It is possible that the Kremlin could now opt to cut off the gas supply to Ukraine, potentially causing difficulty for other European countries that receive their gas via Ukraine.
More top news
Nasa has begun its countdown for a mission to discover whether life might exist on Jupiter's moon Europa.
A mosaic of American film legend Clint Eastwood made from thousands of bullet cases has been created to mark his 85th birthday tomorrow.
Former Lib Dem leader Nick Clegg is among 89 European Union politicians and other senior figures who have been banned from entering Russia.