Border closures along the so-called Balkan route used by refugees have caused a "humanitarian crisis" for Greece, German Foreign Minister Frank-Walter Steinmeier said on Monday.

"Fewer refugees are coming to central Europe because they are stranded in Greece. A humanitarian crisis has arisen there," the Foreign Minister told Funke media group newspapers. "Getting rid of your own problems by putting European partners in distress - this isn't how we should treat one another."

Steinmeier also said that without the refugee deal that the EU recently struck with Turkey, "we would have had 100,000 people trying to survive in the filth and mud on the Greek-Macedonia border." Currently around 11,000 people are stuck at the closed border crossing at Idomeni, with an estimated total of 50,000 stalled in Greece.

"That is why the focus on Europe's external borders, the agreement with Turkey, and the support of Greece is the right way," said Steinmeier. He emphasized that Turkey is a central geographical partner in the struggle to cut down on the European refugee intake, but that the deal must still prove itself in practice.

"You can think it's good, or that it's not," the minister said of the agreement.

He also urged that despite all of the justified criticism of Turkey's internal political developments, the country's efforts to take in millions of refugees over the years should not be overlooked.

Concerning the EU's pledged financial support to Turkey, Steinmeier said the funds "will not flow into the national budget, but rather into very concrete projects to care for refugees."

The EU-Turkey deal states that all migrants who try to illegally enter the EU through Greece will be taken back to Turkey if they cannot prove they have been persecuted in Turkey. In return for each deported Syrian refugee, the EU will accept a Syrian refugee from Turkey through legal channels - up to a maximum of 72,000 people.

rs/kms (AFP, dpa, epd)