Frontline state Greece is feeling the strain of hosting thousands of migrants in camps and Europe must come up with a policy to ease the crisis, the United Nations senior refugee official said on Thursday.
Conditions in the huge open-air camp on the island of Lesbos were "extremely disturbing", United Nations High Commissioner for Refugees Filippo Grandi said on a visit to Greece.
He also expressed misgivings about recent changes that Athens had made to its legal framework for granting asylum.
"Patience and hospitality is now less visible than before," Grandi told reporters in Athens.
On Wednesday, he visited Moria, a camp built for up to 3,000 people but now accommodating more than 15,000.
"Conditions in which people live are extremely disturbing. There is a big sense of despair and a lack of prospects makes the situation difficult," Grandi said.
Greece's new conservative government, elected in July, has taken a tougher stance to the migrant crisis compared to its leftist predecessor.
It says that a chaotic response by the Syriza administration contributed to overcrowding on the islands and virtually adopted an "open door" policy towards arrivals. It has also classed most recent arrivals as economic migrants rather than refugees.
The main gateway into the European Union for more than a million people fleeing conflict in 2015-16, Greece continues to be on the frontline of Europe's migration crisis and has seen a resurgence of arrivals via Turkey in recent months.
Athens has announced plans to shut overcrowded refugee camps on Aegean islands and replace them with holding centres to process new arrivals.
"I made clear to the government that UNHCR policy is against detaining asylum seekers," Grandi said.
Athens wants to move up to 20,000 people to the mainland by the end of the year, expecting the new facilities to be ready by July 2020.
Greece has repeatedly called for a cohesive policy from its European Union partners for an equitable distribution of challenges from the refugee and migration crisis.
"Europe has to get its act together," Grandi said.
The new European Commission president, Ursula von der Leyen, has promised to present a proposal for a revamp of the EU's migration policies next spring.
