The United Nations has warned up to 70,000 migrants and refugees could be trapped in Greece over the coming weeks as countries tighten their borders.
As the human tide shows no sign of abating, the European Union has issued an extraordinary plea to would be migrants: Don't risk your lives and money.
On the Greek border with the Former Yugoslav Republic of Macedonia, tensions are escalating as migrants and refugees find themselves locked in a worsening human bottleneck.
Scores are being turned back because of issues with their paperwork.
This Iraqi man, named Samir, has been told he must return to Lesbos, the Greek island where he landed after his journey across the Mediterranean Sea from the Middle East.
"It's so far. You have to spend 200 euros to go back to there, each person. So, it's very difficult. These people don't have money. They've been here 20 days, for a long time, with a very, very, very bad situation."
And it is a bad situation which appears set to only get worse.
United Nations High Commissioner for Refugees spokesman Babar Baloch, working on the border, says he can sense the relentless pressure building.
"Also, what is worrying is this uncoordinated mechanism of opening and closing of the borders. We, as UNHCR, the humanitarians, we have no idea in terms of what criteria is being put at work when people are admitted. There a lot of those who there are mistakes with their papers, and they have to come back here and return, so this whole procedure is quite worrying, at least for now."
With police forced to use tear gas to quell people trying to storm the border, Macedonian foreign minister Nikola Poposki has defended the tighter controls his country has imposed.
"We are waiting for the numbers of migrants that can be received in the destination countries in Western Europe, and this is going to determine the daily quotas of migrants being allowed to enter Macedonian territory. Essentially, we are in a situation where more and more migrants are arriving in Greek territory, and the registration has to be done at our border and determine which are the eligible asylum seekers that can proceed (along) the road."
Nikola Poposki says Macedonia has no interest in closing its border with its neighbour Greece.
"The last thing we would like to see is a big mess happening across our border in Greece. On the other side, it is clear that the absorption capacity of migrants in mainly receiving EU member states such as Germany, Austria, Sweden and others has reached a certain threshold where it cannot continue next year with the same pace."
The UN special representative for international migration, Peter Sutherland, warns the number of people stranded in Greece could pass 70,000 as people arrive, then get blocked.
"We have the erection of borders -- razor-wire fences, in many instances -- right up through the Balkans into Europe. The inevitable consequence of this is that Greece increasingly becomes a camp for refugees and migrants."
European Union officials are now trying to curb the number of migrants and refugees arriving in Greece from Turkey to fewer than a thousand a day.
That move is part of a broader agreement with Turkey to take more Syrian refugees directly.
After talks with Greek prime minister Alexis Tsipras, European Council president Donald Tusk has issued a direct message to people looking to cross the Mediterranean.
"I want to appeal to all potential illegal economic migrants, wherever you are from, do not come to Europe. Do not believe the smugglers. Do not risk your lives and your money. It is all for nothing. Greece, or any other European country, will no longer be a transit country."
Donald Tusk has called for consensus among the EU members, warning divisions will bring them no closer to solving the crisis.
The tensions are being felt all along the migrants' and refugees' journey to Western Europe.
In the northern French port city of Calais, people have sewn their lips together in protest at the government evicting them from a camp known as The Jungle.
An Iraqi man named Ahmad says life there has been very tough.
"Six days, seven days, after 10 days, can't take shower. Small tent ... cold ... water everywhere ... rain all the time."
