ATHENS, Greece — Greece’s prime minister was heading to high-level meetings in Brussels on Wednesday to try to persuade the country’s creditors to accept a proposal that might unlock much-delayed bailout loans and save the country from financial disaster.

With Greece running out of cash and debt repayments looming as soon as Friday, Alexis Tsipras was to meet Wednesday evening with Jean-Claude Juncker, the head of the European Union’s executive Commission.

“I will go to … explain to him that today more than ever it is necessary for the (creditor) institutions and mainly for the political leadership of Europe to sign up to realism,” Tsipras said before leaving for Brussels.

“We need unity,” he said, speaking of Europe. “I am certain the political leadership of Europe will do what it must.”

Jeroen Dijsselbloem, the eurozone’s top financial official, was also heading to Brussels for the meeting, an official said.

A teleconference between Tispras, German Chancellor Angela Merkel and French President Francois Hollande, tentatively scheduled for Wednesday, had been postponed until Thursday, German finance ministry spokesman Martin Jaeger said.