The European Union Commissioner for migration has admitted that there are three million migrants in Turkey waiting to enter Europe.

European Union (EU) Migration Commissioner Dimitris Avramopoulos admitted that while on a visit to Athens on Monday there are approximately three million migrants waiting to enter Europe, Austrian broadcaster ORF reports. He said that the United Nations has so far registered 2.7 million migrants though there are expected to be even more who are not yet registered.

The news comes as many are growing more and more sceptical of the viability of the migrant deal between Turkey and the EU that came into force in April. While the agreement has led to the slowing down of migration from Turkey, the deal’s success hinges on the demands of visa-free travel that Ankara wishes for all Turkish citizens coming into the EU.

The repeated threats by Turkish President Recep Tayyip Erdoğan and many of his aides and advisers has led some to consider that the deal may collapse entirely. The Austrian Defence Minister Hans-Peter Doskozil has already indicated that his country is preparing for the worst and is looking at increasing police and military presence on the borders of Austria. Mr. Doskozil has said that regardless of whether the deal succeeds or not, “we want to signal that were are able to control our borders”.

In an interview, Greek President Prokopis Pavlopoulos Avramopouos told Greek media that the further development of a solution to the migrant crisis depends increasingly on the success of the EU-Turkey deal. The Greek head of state stressed that the very cohesion of the EU itself could be at risk if the deal fails.

The EU-Turkey deal, along with the closure of the Greek-Macedonian border, led to far fewer migrants crossing over the Balkan route into Austria and Germany. Though over the early months of this year the migrant crisis had calmed, many saw indications that the summer would see a huge increase from the Balkans and from North Africa.

In the past few weeks Italy has been inundated with wave after wave of migrant boats. Last week alone some 4,000 migrants arrived off the coast of Italy. Breitbart London reported earlier in the year that the projections for migrants coming from Africa could be in the millions with some 800,000 currently waiting in Libya to cross the sea.

The Balkan route is also starting to receive more migrants. The Hungarian-Serbian border has seen a new influx of thousands of migrants who have set up a tent city similar to the recently cleared camp in Idomeni, Greece. If the EU-Turkey deal fails, the route could see millions more migrants arrive this year.