David Cameron warned fellow European leaders of the need for the eurozone to take "decisive action" to ensure stability in a high-level conference call to discuss the Greek crisis.
The Prime Minister held a conference call for around 45 minutes with German chancellor Angela Merkel, French president Francois Hollande and Italian prime minister Mario Monti about the latest situation.
It was arranged by president of the European Council Herman van Rompuy ahead of the G8 meeting in the US which starts tomorrow and which all of the leaders will attend.
A Downing Street spokeswoman said it was a "constructive discussion" about the priorities for the talks among some of the world's wealthiest nations in Camp David.
Earlier the Prime Minister had issued a call for action from eurozone states and institutions to support weaker economies like Greece or see the single European currency break up.
The Prime Minister said he would do "whatever it takes to keep Britain safe from the storm", but made clear that the UK could not be immune from the consequences of a collapse of the euro.
He insisted he would not ditch the coalition Government's austerity measures in the face of demands from Labour - and echoed by Mr Hollande - for a shift in focus from austerity to growth.
The eurozone is at a crossroads.
It either has to make-up or it is looking at a potential break-up.
Either Europe has a committed, stable, successful eurozone with an effective firewall, well capitalised and regulated banks, a system of fiscal burden sharing, and supportive monetary policy across the eurozone, or we are in uncharted territory which carries huge risks for everybody.