Slovak Finance Minister Peter Kazimir on Sunday warned that Greece's 'No' referendum result opened the door to the country's departure from the eurozone, becoming the first European minister since the crucial vote to raise the prospect of a so-called "Grexit".

"The nightmare of the 'euro-architects' that a country could leave the club seems like a realistic scenario after Greece voted No today," Kazimir tweeted Sunday as partial results showed Greek voters decisively rejecting creditors' bailout terms in the landmark referendum.