Bitter cold, biting winds and rough winter seas have done little to stem the seemingly endless flow of desperate people fleeing war or poverty for what they hope will be a brighter, safer future in Europe. As 2016 dawns, boatloads continue to reach Greek shores and thousands trudge across Balkan fields and country roads heading north.

More than a million people reached Europe in 2015 in the continent's largest refugee influx since the end of World War II — a crisis that has tested European unity and threatened the vision of a borderless continent. Nearly 3,800 people are estimated to have drowned in the Mediterranean last year, making the journey to Greece or Italy in unseaworthy vessels packed far beyond capacity.

The European Union has pledged to bolster patrols on its external borders and quickly deport economic migrants, while Turkey has agreed to crack down on smugglers operating from its coastline. But those on the front lines of the crisis say the coming year promises to be difficult unless there is a dramatic change.

Greece has borne the brunt of the exodus, with more than 850,000 people reaching the country's shores, nearly all arriving on Greek islands from the nearby Turkish coast.

"The (migrant) flows continue unabated. And on good days, on days when the weather isn't bad, they are increased," Ioannis Mouzalas, Greece's minister responsible for migration issues, told The Associated Press. "This is a problem and shows that Turkey wasn't able — I'm not saying that they didn't want — to respond to the duty and obligation it had undertaken to control the flows and the smugglers from its shores."

Europe's response to the crisis has been fractured, with individual countries, concerned about the sheer scale of the influx, introducing new border controls aimed at limiting the flow. The problem is compounded by the reluctance of many migrants' countries of origin, such as Pakistan, to accept forcible returns.

"If measures are not taken to stop the flows from Turkey and if Europe doesn't solve the problems of the returns as a whole, it will be a very difficult year," Mouzalas warned.

Along the Balkan migrant route, an undetermined number of men, women and children considered economic migrants have found themselves stranded, their hopes of reaching prosperous northern EU countries dashed by recent border closures. Greece, with thousands of miles of coastline, is the only country that cannot feasibly block people from entering without breaking international laws about rescuing those in distress at sea.

"It's a bad sign, this unabated flow that continues," Mouzalas said. "It creates difficulties for us, as the borders have closed for particular categories of people and there is a danger they will be trapped here."

The number of those estimated to be stuck in Greece runs in the thousands. Mohammed Abusaid is one of them.

A baby-faced 27-year-old Moroccan electrician, Abusaid left home with dreams of finding work in Germany or even the United States.

Like tens of thousands before him, he made his way with a group of friends to Turkey and then braved the short but perilous sea crossing to the Greek island of Lesbos in early November.

From there, they headed north only to discover the Macedonian border was open only to those from war-wracked Syria, Afghanistan or Iraq. The young Moroccans now spend their nights huddling for warmth in a tent beneath a straggly tree outside Athens' old airport.

"I'm living here like a tramp. But I'm not a tramp," Abusaid said quietly. "I'm single, my parents are old. I want to look for work. We don't cause trouble, we just want to work."

But Abusaid finds himself trapped in a country battered by a five-year financial crisis that has left unemployment hovering around 25 percent. Desperate, cold and hungry, two of his friends have opted for the voluntary repatriation scheme offered by the International Organization for Migration and are heading home this month. Abusaid says he's pondering following suit.

But he still hopes to make it to northern Europe for a better life, and dreams of America. "I wish I could fly like a bird and go there."

Inside the old airport complex, a shelter has been set up in a former Olympic Games hockey venue but access is limited to vulnerable groups, particularly after theft, looting and fights were reported among groups of men.

"We realize it is very difficult for the new government to handle all these elevated numbers," said Chrysanthi Protogerou, director of the Greek Council for Refugees aid organization. "We were not well prepared and we continue not being well prepared."

She called for "better coordination, to make an even bigger effort, because the problem is becoming huge."

Battered on the one side by a massive wave of desperate people risking their lives to reach its islands and on the other by border restrictions, Greece is struggling.

"It's a situation to which we are being subjected without bearing any responsibility for it and without being able to control it," said Mouzalas. "Whatever measures we take here, if on the Turkish side the smugglers increase the flows, we can't cope."

"We have a vast sea and countless islands," he added. "If a ground intervention occurs in Syria, we can't deal with this wave of refugees."

The problem, the beleaguered minister said, "is happening in Greece but it is a European problem and the solution must be a European one."

Nearly all new arrivals are aiming for wealthy northern European countries, with Germany and Sweden the favorites. Both stood out for trying to maintain a generous welcome even as numbers swelled, with German Chancellor Angela Merkel famously proclaiming "we will manage it."

Germany received about 1 million asylum-seekers this year and Sweden more than 150,000.

However, toward the end of the year even those two shifted course. Germany introduced border checks in September and Sweden in November. Sweden is now taking steps to keep people from even reaching the border and as of Monday will require passengers boarding Sweden-bound trains in neighboring Denmark to show ID. The crisis has strained relations between the Scandinavian neighbors.

Further down the migrant trail, refugees trickle steadily into Macedonia and Serbia, although authorities say numbers have decreased "drastically."

In a Serbian refugee center in Presevo near the Macedonian border, a baby wearing a yellow cap and oversized gloves blinked in the winter sun while a woman slowly combed a girl's long, black hair.

Although trains and buses are still crowded, Macedonia's border controls seem to be working.

"The number of migrants going through has drastically declined," said Presevo camp deputy manager Slobodan Savovic. "That means the numbers have more than halved when compared to September, when we had as much as 10,000 people per day."