Hong Kong (CNN)Following a referendum in which Greeks voted against accepting new austerity measures, European leaders have given Greece one last deadline to get its economy into shape by Sunday or risk leaving the eurozone. Here are five major power players to keep an eye on.
Greece's debt crisis: A who's who
Greek Prime Minister Tsipras led the hard-left Syriza party to victory in January, promising an end to unpopular austerity measures that have left one in four Greeks living in poverty.
On Sunday, he successfully persuaded 61% of Greek voters to vote "No" against international creditor demands.
Speaking afterward in a televized address, Tsipras said: "Given the unfavorable conditions last week, you have made a very brave choice," before going on to say that he understood it was "not a mandate to clash with Europe."
Tsipras held talks Tuesday with eurozone leaders in Brussels, where he asked for temporary help to allow Greece to meet a crucial debt repayment to the European Central Bank on July 20.
Newly sworn-in Tsakalatos replaces Yanis Varoufakis who abruptly announced his resignation on Monday.
The Oxford-educated economist had already taken over from Varoufakis as Greece's lead negotiator in April. While the soft-spoken former university lecturer is of a calmer temperament, ideologically Tsakalatos is unlikely to stray too much from his predecessor's path.
In March, he said: "Some European governments will be arguing that we should not give problematic Greeks special treatment. You know that we are not asking for special treatment but for equal treatment in a Europe of equals."
Tsakalatos' first task will be to convince the European Central Bank to provide an injection of emergency funds before Greece's banks run dry, which could happen as soon as this week.
As head of the largest economy in Europe and Greek's largest creditor, Merkel wields enormous influence in the EU talks. Germany is reluctant to give in to new concessions after pledging tens of billions in bailout money for half a decade.
Like other exasperated creditors, including France, Italy, Spain and the "troika" -- the tripartite committee made up of the European Commission, the European Central Bank (ECB) and the International Monetary Fund (IMF) -- Germany blames Athens for failing to carry through economic reforms required under its bailout agreement.
On one hand, Merkel is trying to avert a full-scale break up of the eurozone while also trying to appease hardline elements in Germany, including the country's Finance Minister Wolfgang Schaeuble, who insists that the EU could survive a so-called "Grexit."
"Greece has received unprecedented solidarity over the last five years," Merkel said on Monday in Paris, where she was meeting French President Francois Hollande to discuss the crisis. "The basic principle still applies; help in return for reforms."
"We are now waiting for very specific proposals from the Greek Prime Minister to enable Greece to return to prosperity," Merkel said.
A former prime minister of Luxembourg, Juncker was appointed head of the European Commission, the executive branch of the European Union, last November. In the lead-up to Sunday's referendum, Juncker expressed that he felt deeply distressed and even betrayed by Tsipras' rejection of the proposal and pleaded with Greeks to vote "Yes" and accept the terms of a new austerity deal.
"We will never let the Greek people down. And we know the Greek people don't want to let down the European Union," before saying, "you should not commit suicide because you're afraid of death."
After the vote which resulted in a landslide "no" rejecting the austerity terms, the European Commission released a statement saying it "takes note of and respects the result of the referendum in Greece."
In a Q&A session that followed Tuesday's emergency summit, Juncker said he was "strongly in favor of keeping Greece in the euro area," but that Greece's last chance to present a viable proposal for that would be Friday morning. He added that while he was against the Grexit, the Commission was prepared for everything, including that scenario.
Known as "guardian of the euro," Draghi oversees the institution that stands between Greece and a full-fledged economic collapse. For the better part of this year, the ECB has been keeping the Greek banks afloat through an emergency liquidity assistance program.
However, it clamped down on cash flows after Greece missed its payment to the IMF forcing Greek banks to shut and implement a daily cap of €60 ($65) on ATM withdrawals.
"I can assure you the ECB is doing all it can to facilitate a successful outcome. Liquidity will continue to be extended as long as Greek banks continue to be solvent," Draghi said last month.
Following Sunday's referendum, the ECB decided to tighten the liquidity further. The ECB's governing council meets in Frankfurt on Wednesday to decide on next steps. The larger looming deadline is July 20, when Greece is due to repay its debts to the ECB. A default could precipitate an exit from the EU.