Speaking to the news agency AFP during a visit to Washington, Greece's migration minister, Giorgos Koumoutsakos, expressed concerns over threats by President Recep Tayyip Erdogan and other Turkish officials to "open the gates" to Europe if it does not provide more support.

When Turkey "keeps repeating that we're going to open the floodgates, what they (migrants) do is they move closer to the floodgates waiting for them to open," Koumoutsakos said, citing a 240 percent increase in migrant arrivals in Greece since May.

Koumoutsakos said that Greece wanted the European Union to "positively consider" Turkey's request for assistance beyond the money committed in 2016 to stop migrants.

"But the fact that Turkey asked for this money by blackmail or threats does not create the necessary political climate for the Europeans to decide to give the money," he said.

"Europe cannot act under threats or blackmail. As Europeans should understand the situation that the Turks are faced with, Ankara should on its part realize that this is not the way to deal with Europe," Koumoutsakos said.

Merkel 'ready to help' Turkey

Germany's leader, Angela Merkel, said on Wednesday that Germany was prepared to increase assistance to Turkey for sheltering an estimated 3.5 million mostly Syrian refugees. "I am ready for that," Merkel said during a European People's Party congress in Zagreb.

In a deal with EU member states in 2016, Turkey committed to trying to stop migrants from reaching the Greek Aegean islands and to take back migrants whose bids for asylum in Europe were rejected.

In exchange, the EU offered Turkey 6 billion euros, of which 5.6 billion euros has been provided, the European Commission said in September. The deal has not stopped migrants from reaching the Greek islands, where asylum seekers are left waiting for long periods in dangerously overcrowded camps.

Critics say that a lack of resources to process asylum claims in Greece has created a two-year case backlog, while only a small number of people have been sent back to Turkey since the deal was agreed upon.

Closed camps planned for islands

The Greek government this week announced plans to overhaul the camps. New, closed facilities will be built where migrants will be detained until they are either granted refugee status or rejected and sent back to Turkey, government spokesperson Stelios Petsas said.

All those estimated to be "true refugees" will be brought to camps on the mainland, Petsas said in a news conference in Athens on Wednesday.

The planned new camps on the islands will have capacity for 5,000 residents each, with housing in container homes, water supply, electricity, toilets and bathrooms.

An additional 500 staff will be employed to speed up the processing of asylum applications and a state official will be appointed to care for an estimated 5,000 unaccompanied minors stranded in Greece.

Critical reception

The Greek branch of the UN refugee agency, UNHCR, welcomed the government's new plan. "The unaccompanied minors, the most vulnerable group, must be a priority," UNHCR spokesperson in Athens, Boris Cheshirkov, told dpa.

But he expressed concern that people, mostly men from Syria, Afghanistan and Congo, may not get a fair chance for asylum once they are sent to the closed camps. Cheshirkov also said that Europe should show more solidarity with Greece, which hosts more refugees and migrants than Italy, Spain and Malta combined, dpa reports.

German left party spokesperson Ulla Jelpke was critical of the planned detention centers, calling it a "dirty alternative." "Fleeing is not a crime and locking people up is inhumane," she said.

The mayor of Samos island, Giogios Stantzos, threatened to resign if the government went ahead with the plan. He said an entire "city of migrants" was not possible, adding that the government had earlier proposed a much smaller facility.

Migration Minister Koumoutsakos, however, said that Greek residents of the islands had "migration fatigue," afp reports.

He added that, unlike the previous left-wing government in Greece, "we are looking not only at the humanitarian aspect, but the security aspect."

With dpa, afp