Greece has submitted a proposal for an agreement with its creditors, the country's prime minister said Tuesday, as Athens seeks a deal that will unlock desperately needed rescue money.

Alexis Tspiras said the ball was now in Europe's court to prevent the potential breakup of the European Union. Without more rescue loans, Greece could default on its debts this month and potentially drop out of Europe's currency bloc.

"It is now clear that the decision for whether they want to adapt to realism and emerge from the crisis without the division of Europe, the decision belongs to the political leadership of Europe," he said.

Tsipras gave no indication of what the proposal might include, other than to say it was realistic. It was submitted to the European Central Bank, International Monetary Fund and European Commission on Monday night.

His comments come the morning after the leaders of Germany, France, the IMF, ECB and European Commission held an emergency meeting about Greece in Berlin.

According to a German government statement, all present at that meeting pledged to work "with great intensity" to seek a solution.

Greece must repay a total of about 1.6 billion euros to the IMF this month, with the first installment due this Friday. It is uncertain that the country can afford to pay the roughly 303 million euro installment on Friday, increasing the sense of urgency for an agreement to be reached by then that will unlock the remaining 7.2 billion euros of its bailout.

There have been suggestions Greece could seek to bundle all the money it owes the IMF this month into one payment on June 30 — an option which is permitted under IMF rules but rarely used. Taking that route could buy more time to secure a deal, although Athens has not indicated it is considering it.

"I am optimistic," Tsipras said. "I believe the political leadership of Europe will view our proposals with respect."

At Monday night's talks in Berlin, the ECB's Mario Draghi and IMF head Christine Lagarde joined a previously scheduled meeting at the chancellery between German Chancellor Angela Merkel, French President Francois Hollande and the EU's Commission President Jean-Claude Juncker.

A German government statement said the five pledged to work "with great intensity" to seek a solution and agreed to stay in close contact with each other and also with the Greek government. The leaders "were in very close contact during the last days and will continue to be — with each other as well as, of course, with the Greek government."

Tsipras' government, a coalition of his radical left Syriza party and a small nationalist party, was elected in January on promises of repealing the deeply resented austerity measures that accompanied the international bailout that has kept Greece afloat for the last five years.

For the last four months the government has been locked in tortuous negotiations with its creditors over what reforms Athens must take in order to receive the final installment of its 240 billion euro bailout. Major sticking points have included labor reform and further curtailing pensions.