The border controls that are hampering movement within the European Union's passport-free Schengen area should be lifted by December, the European Commission said Friday, as it presented a new plan to get a better handle on the migration crisis.
The Schengen area is one of the continent's most-cherished achievements, with its 26 participating countries normally allowing free travel across their bloc, without the need for passports or border checks.
But several Schengen nations have re-introduced internal border controls since September in an emergency bid to stem the most significant migration flows Europe has seen in decades. More than 1 million migrants and asylum seekers reached its shores last year.
There are fears that the migration crisis could ultimately lead Schengen to disintegrate.
Migration-related border controls are currently active in Austria, Belgium, Denmark, Germany, Norway and Sweden.
"While [these] ... are according to the rules, we cannot forget the objective: that they are indeed exceptional and temporary, and that we should return to a border-free internal Schengen zone as soon as possible," EU Migration Commissioner Dimitris Avramopoulos said.
Such controls hamper not only the free movement of people, but also generate "significant economic costs," the commission warned.
The European Union's executive estimates that a full re-establishment of border controls within Schengen would have an immediate direct cost of 5-18 billion euros (5.5-19.7 billion dollars).
The road transport of goods would become more expensive, workers would lose time crossing borders and tourists could be discouraged from traveling within Europe, the commission predicted.
The Brussels institution said that it is ready to allow border controls throughout this year, but the plan released Friday also calls for all controls to be lifted by December so that Schengen can return to normal by the end of the year.
That process must be accompanied by a better protection of Schengen's external borders and an end to the practice of migrants who want to reach wealthy northern Europe simply being waved through by countries further south.
The commission's plan calls for a new European border and coastguard to start operating in the summer and for overwhelmed Greece to receive more support in securing its border with Turkey.
"We cannot have free movement internally if we cannot manage our external borders effectively," Avramopoulos noted.
Greece is also set to receive 3.5 million euros in emergency funding to help fund the staff processing migrants once they arrive on the country's islands, the commission announced Friday.
There has been speculation that the country could be excluded from Schengen if it does not do a better job of restricting migrants' movements, but the commissioner said there is no "ultimatum" that would see a country removed.
"We all have to work within the Schengen area and defend the Schengen zone," Avramopoulos said.
"The EU was built on solidarity and resilience, out of fragmentation," he added. "It is precisely in testing times like these, that we should rely on that solidarity and that resilience, and deepen mutual trust, because it is the only way to move ahead."