British bank HSBC fired six staff after they filmed a mock Islamic State-style execution video during a team-building day out and posted footage online, a spokesman confirmed on Tuesday.

The bank described the video, showing staff members in balaclavas holding a fake knife over a kneeling man in an orange jumpsuit, as "abhorrent".

France can't take the risk of Greece leaving the eurozone, which would have an effect across the globe, the prime minister said on Tuesday, adding that the basis for a deal with Athens was there.

"France is convinced that we can't take the risk of Greece leaving the eurozone," a move that would affect economies across the globe, Manuel Valls told French radio. "The basis for a deal exists... There is no taboo subject when it comes to (Greek) debt, on the restructuring."

Greek Foreign Minister Nikos Kotzias on Monday ruled out his country's exit from the EU and called for calm after Greek voters rejected bailout terms of international creditors.

"Europe without Greece? It's a joke," the visiting foreign minister told Israel's private Channel 2 television.

The White House urged Greece and EU leaders Monday to find a compromise to keep the cash-strapped country in the eurozone, after Greeks voted resoundingly to reject an austerity-based bailout.

"The referendum is over, but our view here at the White House remains the same," said spokesman Josh Earnest.

Greek banks will remain closed on Tuesday and Wednesday with limits on daily withdrawals unchanged, officials said on Monday as the European Central Bank maintained its liquidity assistance to the nation's beleaguered lenders.

"Until Wednesday evening we continue as things stand today," said Louka Katseli, chairwoman of the National Bank of Greece. 

The five-month tenure of Greece's pugnacious former finance minister Yanis Varoufakis, who notably accused the country's creditors of "terrorism", was marked by his outspokenness and refusal to submit to convention.

Stepping down on Monday, a day after the 'No' referendum, the flamboyant Varoufakis launched a parting shot saying: "Soon after the announcement of the referendum results, I was made aware of a certain preference by some Eurogroup participants, and assorted 'partners', for my 'absence' from its meetings...I shall wear the creditors’ loathing with pride."

Vote 'Yes' or leave the euro: European leaders talked tough ahead of Greece's momentous referendum, but that threat could seriously complicate a return to the negotiating table after Greeks said an emphatic 'No' to more austerity.

Ahead of Sunday's referendum European politicians had queued up to take an uncompromising line, warning that a 'No' vote could bring dire consequences. 

The German banking federation said Monday it sees little danger of contagion for the wider euro area from the Greek crisis after Greece voted against the austerity measures demanded by its creditors.

"Regardless of the outcome of the referendum, we do not expect an increased risk of contagion for other euro countries," the head of the BdB federation, Michael Kemmer, said in a statement. 

Beijing on Monday named a former vice minister of finance as its preferred candidate to head the China-led Asian Infrastructure Investment Bank (AIIB), a potential rival to the Washington-based World Bank.

"The Chinese government has officially nominated Jin Liqun to be China's candidate for the presidency of the AIIB," the finance ministry said in a statement.

European stock markets slid at the start of trading on Monday after eurozone member Greece rejected creditors' austerity demands in a weekend referendum.

Frankfurt's DAX 30 shed 2.11 percent to 10,825.06 points and the CAC 40 in Paris fell 2.06 percent to 4,709.01 points. Outside the eurozone, the FTSE 100 index lost 1.07 percent to stand at 6,515.67 compared with Friday's close.