"Turbulence may ensue" if no agreement is struck between Greece and its international bailout supervisors soon, the vice-president of the European Central Bank (ECB) has told CNBC.
"The Greek public finance is stressed for liquidity and so it is necessary to have an agreement as quickly as possible," Vitor Constancio told CNBC on Thursday.
Greece suggested on Wednesday that its was nearing a "staff level agreement" with its creditors—a development swiftly denied by its global creditors.
European stocks fell back as a result on Thursday, having rallied sharply in the previous session. The euro also pared some gains and U.K. Gilts and German Bunds—seen as a "safe haven" asset comparable to U.S. Treasurys—gained.
The ECB is one of the so-called Troika supervising Greece's bailout, along with the International Monetary Fund and the European Commission. The three institutions and Greece's far left government has been battling for months over an aid-for-reforms deal, with major loan repayment deadlines looming next month.
Constancio said that "turbulence" could include an upsurge in capital outflows from the Hellenic Republic.
"Fortunately the outflows from Greece have subsided recently—well, that may chance in a negative way and that of course will put further pressure on the liquidity situation of Greece," he told CNBC.
Constancio ruled out the possibility of a "Grexit" from the euro zone, but not the prospect of Greece defaulting on its international loans.