The UN refugee agency (UNHCR) has criticized European countries over a "domino-like" buildup of tens of thousands of refugees in Greece, warning that the continent is on the "cusp of a self-induced" humanitarian crisis if governments fail to work together.
The UNHCR's warning on March 1 came after Macedonia used tear gas and stun grenades to repel hundreds of migrants attempting to ram through a barbed-wire fence at a crossing in Idomeni.
The UNHCR also warned that crowded conditions in Greece have led to a "completely unmanageable" situation that includes shortages of food, shelter, and water among migrants, stoking tensions and "fueling violence."
"We are faced with an extremely alarming situation at the moment, with Europe on the cusp of a new and largely self-induced humanitarian crisis," UNHCR spokesman Adrian Edwards told RFE/RL on March 1.
Edwards said Mediterranean arrivals in January and February totaled 131,000, compared to around 147,000 in the first six months of last year, more than 122,000 of them coming to Greece after fleeing conflict in Syria.
The UN agency said an estimated 24,000 refugees were in need of accommodation in Greece as of February 29, while Greek police said the number of people massed at the Idomeni crossing has reached 10,000.
The UNHCR spokesman noted that "compared to refugee crises that we see in the Syria region, in Afghanistan, in parts of Africa, these are still relatively small numbers."
Greece has been left to cope with much of the burden of new arrivals since a cap on migrant entries was imposed by its Balkan neighbors and Austria, which is further along a route used by people trying to reach Germany and other rich European Union countries.
Large numbers of migrants have built up in the country as a result.
WATCH: Migrants Rush Greece-Macedonia Border Fence (February 29)
"Governments across Europe are not working together despite agreements that have already been reached in a number of areas," Edwards said.
The 28-member European Union, which has been struggling to cope with a surge in migration that saw more than 1 million new arrivals last year, has been criticized for its failure to show a united front in protecting the rights of the refugees.
"Country after country is imposing new border restrictions and a series of inconsistent practices across Europe causing both unnecessary suffering and risk being at variance with EU and international law," Edwards said. "And most serious still, bring Europe back into a crisis over a situation which should be entirely manageable."
The UNHCR said that for many months European countries simply waved refugees and migrants through without any proper screening system to establish who was a refugee and who wasn't and without functioning mechanisms that could have ensured that help is available for people who need asylum.
"Now we're seeing a turning of the tide that's forcing people country-by-country domino-like back towards Greece into a situation which is completely unmanageable. We urgently, urgently need now to see Europe return to trying to address this together," Edwards told RFE/RL.
Meanwhile the border remained closed on March 1, as Macedonian President Gjorge Ivanov warned he could shut down the Balkan migrant route altogether later this year.
Ivanov told German newspaper Der Spiegel that, when Austria reaches its limit of 37,500 migrant entries, Macedonia will close its border with Greece, effectively shutting down a path to northern Europe used by hundreds of thousands of migrants.
"When Austria reaches its limit, it will happen," Ivanov said, suggesting that could occur very soon, "perhaps right at this moment."
The UNHCR warned that such moves "risk being at variance with EU and international law and are causing unnecessary suffering to many people."
Edwards urged European countries to work together to solve this "manageable" situation instead of taking unilateral action.
"The crisis that Europe has now is one of failing to work together to address this properly. It's a self-induced crisis. It's also one solvable and avoidable," he said.