The United Nations refugee agency (UNHCR) on Friday called on Greece to take control of the "total chaos" on Mediterranean islands, where 50,000 refugees and migrants landed in July — 20,000 more than the previous month — and are wallowing in “totally shameful” conditions.

After visiting the Greek islands of Lesbos, Kos and Chios, the agency’s European director, Vincent Cochetel, expressed shock over how little Greece and other European countries have done to assist the refugees and migrants.

"I've been working 30 years with UNHCR [and] I have never seen a situation like that...This is the European Union, and this is totally shameful," Cochetel told reporters on Friday.

"In terms of water, in terms of sanitation, in terms of food assistance, it's totally inadequate. On most of the islands, there is no reception capacity, people are not sleeping under any form of roof. So it's total chaos on the islands."

Since January, an estimated 124,000 refugees and migrants have arrived on Greek shores, representing a 750 percent increase from the same period in 2014, according to UNHCR. Almost all of them are refugees from Syria and Afghanistan, the agency said.

In most cases, refugees and migrants who arrive on the Greek islands find no assistance, as there are no reception facilities. Many are forced to sleep outdoors in inadequate conditions and rely on food and water handouts from volunteer aid workers, Cochetel said.

After a few days, the refugees and migrants are transferred to Athens, where again "there is nothing waiting for them," Cochetel added, noting that the entire country is only set up to receive and care for 1,100 people.

The dire conditions could explain why only a small fraction of those who arrive on the Greek islands apply for asylum. Between January and June, only 6,200 refugees and migrants applied for asylum in Greece, according to UNHCR. Instead, most have illegally traveled to neighboring European countries, sparking a multitude of migrant crises across the continent.

While Cochetel demanded urgent action from Athens, Greek Prime Minister Alexis Tsipras said Friday that the country's infrastructure could not handle the influx of refugees and migrants and asked the European Union to help.

"Now is the time to see if the EU is the EU of solidarity or an EU that has everyone trying to protect their borders," Tsipras said. "The immigrant flow to Greece is beyond of what our state infrastructure can handle."

Greece is currently negotiating with creditors a third multi-billion dollar bailout package to stave off financial collapse. Given Greece’s poor economic situation, Cochetel agreed that European countries should assist Athens in addressing its migrant crisis.

However, some EU members have been reluctant to intercede. Britain, which is currently struggling to prevent migrants from entering its territory through the Channel Tunnel, refuses to participate in European efforts to resettle refugees and migrants. Hungary is also preparing to build a fence along its border, where migrants from the east seek to enter.

Al Jazeera and wire services