The director of the UN office in Geneva, Michael Møller, has warned that Europe must prepare for the arrival of millions more migrants from Africa, Asia and the Middle East.

The migrants arriving in Italy are overwhelmingly economic migrants seeking a better life in Europe. Only a very small number appear to be legitimate asylum seekers or refugees fleeing warzones.

Turkey appears determined to flood Europe with migrants either way: with Europe's permission by means of visa-free travel, or without Europe's permission, as retribution for failing to provide visa-free travel.

"In terms of public order and internal security, I simply need to know who is coming to our country." — Austrian Interior Minister Wolfgang Sobotka.

The European Union has called on its member states to lift border controls — introduced at the height of the migration crisis in September 2015 — within the next six months.

The return to open borders, which would allow for passport-free travel across the EU, comes at a time when the number of migrants crossing the Mediterranean continues to rise, and when Turkish authorities increasingly have been threatening to renege on a border deal that has lessened the flow of migrants from Turkey to Europe.

Critics say that lifting the border controls now could trigger another, even greater, migration crisis by encouraging potentially millions of new migrants from Africa, Asia and the Middle East to begin making their way to Europe. It would also allow jihadists to cross European borders undetected to carry out attacks when and where they wish.

At a press conference in Brussels on May 2, the EU Commissioner in charge of migration, Dimitris Avramopoulos, called on Austria, Denmark, Germany, Norway and Sweden — among the wealthiest and most sought after destinations in Europe for migrants — to phase out the temporary controls currently in place at their internal Schengen borders over the next six months.

The so-called Schengen Agreement, which took effect in March 1995, abolished many of the EU's internal borders, enabling passport-free movement across most of the bloc. The Schengen Agreement, along with the single European currency, are fundamental pillars of the European Union and essential building-blocks for constructing a United States of Europe. With the long-term sustainability of the single currency and open borders in question, advocates of European federalism are keen to preserve both.

Avramopoulos, who argued that border controls are "not in the European spirit of solidarity and cooperation," said:

"The time has come to take the last concrete steps to gradually return to a normal functioning of the Schengen Area. This is our goal, and it remains unchanged. A fully functioning Schengen area, free from internal border controls. Schengen is one of the greatest achievements of the European project. We must do everything to protect it."

The temporary border controls were established in September 2015, after hundreds of thousands of migrants arrived in Europe, and when EU member states, led by Germany, gave special permission to some EU countries to impose emergency controls for up to two years. Since then, the European Union has approved six-month extensions of controls at the German-Austrian border, at Austria's frontiers with Hungary and Slovenia and at Danish, Swedish and Norwegian borders (Norway is a member of Schengen but not the EU). Several countries have argued that they need border controls to combat the threat of Islamic militancy.

On May 2, Sweden, which claims to conduct the most border checks among the EU countries, announced that it will lift controls at its border with Denmark. Sweden received 81,000 asylum seekers in 2014; 163,000 in 2015; 29,000 in 2016, and the same is expected for 2017.

On April 26, Austria called for an indefinite extension of border controls. "In terms of public order and internal security, I simply need to know who is coming to our country," Austrian Interior Minister Wolfgang Sobotka said. Austria, which accepted some 90,000 migrants in 2015, also called for a "postponement" of the EU refugee distribution program, which requires EU member states to accept a mandatory and proportional distribution of asylum-seekers who arrive in other member nations.

On March 9, Norway extended border controls for another three months.

On January 26, Denmark extended border controls for another four months. Integration Minister Inger Støjberg said that her government would extend its border controls "until European borders are under control."

On January 19, Germany and Austria announced that border controls between their countries would continue indefinitely, "as long as the EU external border is not adequately protected."

Meanwhile, the number of migrants making their way to Europe is once again trending higher. Of the 30,465 migrants who reached Europe during the first quarter of 2017, 24,292 (80%) arrived in Italy, 4,407 arrived in Greece, 1,510 arrived in Spain and 256 arrived in Bulgaria, according to the International Organization for Migration (IOM).

By way of comparison, the number of arrivals to Europe during each of the first three months of 2017 exceeded those who arrived during the same time period in 2015, the year in which migration to Europe reached unprecedented levels.

The trend is expected to continue throughout 2017. Better weather is already bringing about a surge of migrants crossing the Mediterranean Sea from Libya to Europe. During just one week in April, for example, a total of 9,661 migrants reached the shores of Italy.

The migrants arriving there are overwhelmingly economic migrants seeking a better life in Europe. Only a very small number appear to be legitimate asylum seekers or refugees fleeing warzones. According to the IOM, the migrants who reached Italy during the first three months of 2017 are, in descending order, from: Guinea, Nigeria, Bangladesh, Ivory Coast, Gambia, Senegal, Morocco, Mali, Somalia and Eritrea.

In February, Italy reached a deal with the UN-backed government in Tripoli to hold migrants in camps in Libya in exchange for money to fight human traffickers. The agreement was endorsed by both the European Union and Germany.

On May 2, however, German Foreign Minister Sigmar Gabriel reversed course by saying the deal ignored the "catastrophic conditions" in Libya and would not curb migration. He said that Germany now favored tackling migration by fighting instability in Africa:

"What we are trying instead is to help stabilize the countries on the continent. But that is difficult. We will have to show staying power, stamina and patience. This is in the interest of Africans but also in the interest of Europeans."

Gabriel's long-term solution — which in the best of circumstances could take decades to bear fruit — implies that mass migration from Africa to Europe will continue unabated for many years to come.

Italy has emerged as Europe's main point of entry for migrants largely because of an agreement the European Union signed with Turkey in March 2016 to stem migration from Turkey to Greece. In recent weeks, however, Turkish authorities have threatened to back out of the deal because, according to them, the EU has failed to honor its end of the bargain.

Under the agreement, the EU pledged to pay Turkey €3 billion ($3.4 billion), as well as grant visa-free travel to Europe for Turkey's 78 million citizens, and to restart accession talks for Turkey to join the bloc. In exchange, Turkey agreed to take back all migrants and refugees who reach Greece via Turkey.

After the deal was reached, the number of migrants reaching Greece dropped sharply, although not completely. According to data supplied by the European Union on April 12, a total of 30,565 migrants reached Greece since the migrant deal took effect. Only 944 of those migrants have been returned to Turkey. Still, this is in sharp contrast to the hundreds of thousands of migrants who entered Greece at the height of the migration crisis. Turkey's continued cooperation is essential to keep the migration floodgates closed.

On April 22, Turkey's Minister for EU Affairs, Ömer Çelik, issued an ultimatum, warning the European Union that if it does not grant Turkish citizens visa-free travel by the end of May, Turkey would suspend the migrant deal and flood Europe with migrants.

On March 17, Turkey's Interior Minister Süleyman Soylu warned that his country would "blow the mind" of Europe and renege on the deal by sending 15,000 Syrian refugees a month to Europe:

"We have a readmission deal. I'm telling you Europe, do you have that courage? If you want, we'll send the 15,000 refugees to you that we don't send each month and blow your mind. You have to keep in mind that you can't design a game in this region apart from Turkey."

In February 2016, Turkish President Recep Tayyip Erdoğan had already threatened to send millions of migrants to Europe. "We can open the doors to Greece and Bulgaria anytime and we can put the refugees on buses," he told European Commission President Jean-Claude Juncker. In a speech, he signaled that he was running out of patience:

"We do not have the word 'idiot' written on our foreheads. We will be patient, but we will do what we have to. Don't think that the planes and the buses are there for nothing."

European officials say that to qualify for the visa waiver, Turkey must meet 72 conditions, including the most important one: relaxing its stringent anti-terrorism laws, which are being used to silence critics of Erdoğan, especially since the failed coup in July 2016. Turkey has vowed not to comply with the EU's demands.

Critics of visa liberalization fear that millions of Turkish nationals may end up migrating to Europe. The Austrian newsmagazine, Wochenblick, recently reported that 11 million Turks are living in poverty and "many of them are dreaming of moving to central Europe."

Other analysts believe Erdoğan views the visa waiver as an opportunity to "export" Turkey's "Kurdish Problem" to Germany. According to Bavarian Finance Minister Markus Söder, millions of Kurds are poised to take advantage of the visa waiver to flee to Germany to escape persecution at the hands of Erdoğan: "We are importing an internal Turkish conflict," he warned. "In the end, fewer migrants may arrive by boat, but more will arrive by airplane."

The European Union now finds itself in a Catch-22 situation. Turkey appears determined to flood Europe with migrants either way: with Europe's permission by means of visa-free travel, or without Europe's permission, as retribution for failing to provide visa-free travel.

Greek officials recently revealed that they have drawn up emergency plans to cope with a new migrant crisis. Turkey is hosting some three million migrants from Syria and Iraq, many of whom are presumably waiting for an opportunity to flee to Europe.

Italy is also bracing for the worst. Up to a million people, mainly from Bangladesh, Egypt, Mali, Niger, Nigeria, Sudan and Syria are now in Libya waiting to cross the Mediterranean Sea, according to the IOM.

The director of the United Nations office in Geneva, Michael Møller, has warned that Europe must prepare for the arrival of millions more migrants from Africa, Asia and the Middle East. In an interview with The Times, Møller, a Dane, said:

"What we have been seeing is one of the biggest human migrations in history. And it's just going to accelerate. Young people all have cellphones and they can see what's happening in other parts of the world, and that acts as a magnet."

German Development Minister Gerd Müller has echoed that warning:

"The biggest migration movements are still ahead: Africa's population will double in the next decades. A country like Egypt will grow to 100 million people, Nigeria to 400 million. In our digital age with the internet and mobile phones, everyone knows about our prosperity and lifestyle."

Müller added that only 10% of those currently on the move have reached Europe: "Eight to ten million migrants are still on the way."