Greek Prime Minister Alexis Tsipras is due to meet German Chancellor Angela Merkel amid mounting concern that Athens is running out of money.
The two countries have been at odds over Greece’s efforts to renegotiate the terms of its international bailout.
It follows a pledge from the European Union (EU) to provide €2bn (£1.45bn) to Greece to ease what it called the country’s “humanitarian crisis”.
But Mrs Merkel said on Friday there would be no new money without reforms.
European Commission President Jean-Claude Juncker said the €2bn fund would be spent on growth and “social cohesion” in Greece.
“Humanitarian crisis, it has been called, and it is indeed a humanitarian crisis,” he said.
He said the EU would provide Greece with €2bn worth of development funds to boost economic growth, cut youth unemployment and help the poor.
Greek Prime Minister Alexis Tsipras welcomed the move, stressing a common need to tackle the humanitarian crisis.