Greek Prime Minister Alexis Tsipras is expected to present new proposals at a Eurozone emergency summit on his country's growing debt crisis, BBC News reports.

The plan is said to include a demand for Greece's debt to be cut by up to 30%, after voters rejected the terms of an international bailout on Sunday, July 5.

Athens has been urged to make "serious" proposals as Greece faces the risk of default on its $331bn debt.

Greece's banks are to stay closed on Tuesday and Wednesday.

Meanwhile, global stock markets proved resilient on Tuesday despite Greece's rejection of the bailout terms, according to the BBC.

Eurozone finance ministers will begin their meeting in Brussels later on Tuesday before a full summit of eurozone leaders.

Central to any negotiations will be new Greek Finance Minister Euclid Tsakalotos, who replaced outspoken Yanis Varoufakis on Monday. Tsakalotos has admitted he is nervous and worried about the crisis, but said Greece deserved a better deal.

However, Germany earlier warned against any unconditional write-off of Greece's debt, saying it would destroy the single currency.

"I really hope that the Greek government - if it wants to enter negotiations again - will accept that the other 18 member states of the euro can't just go along with an unconditional haircut [debt write-off]," said German Economy Minister Sigmar Gabriel.

Meanwhile, the European Central Bank (ECB) said it would maintain existing levels of emergency cash support for Greek banks, which are running out of funds and on the verge of collapse.

However, it told the banks to lodge more collateral with the Bank of Greece, reducing the amount of spare cash the banks have.

On Monday, French President Francois Hollande and German Chancellor Angela Merkel said the door was still open for debt negotiations.

"It is now up to the government of Alexis Tsipras to make serious, credible proposals so that this willingness to stay in the eurozone can translate into a lasting program," Hollande said.

Merkel added that Tsipras should offer "precise suggestions... for a medium-term program that will lead Greece to prosperity and growth again."

Greece's last bailout expired last Tuesday and Greece missed a €1.6bn payment to the IMF.

The European Commission - one of the "troika" of creditors along with the IMF and the ECB - wanted Athens to raise taxes and slash welfare spending to meet its debt obligations. Greece's Syriza-led left-wing government, which was elected in January on an anti-austerity platform, said creditors had tried to use fear to put pressure on Greeks.