Officials from the UN Refugee Agency (UNHCR) have visited Greece to assess the refugee crisis in the country, where some 124,000 refugees and migrants have arrived by sea this year, mainly on the islands of Lesvos, Chios, Kos, Samos and Leros, a UN spokesman told reporters Friday.

"This represents a staggering increase of 750 percent compared to the same period last year," UN spokesman Stephane Dujarric said at a daily news briefing here. "In July alone, 50,000 new arrivals have been reported, 20,000 more than the previous month -- an increase of more than 70 percent in just one month."

This humanitarian emergency requires an urgent Greek and European response, said the UN spokesman, quoting UNHCR. The vast majority of those coming to Greece are from countries experiencing conflict or human rights violations, mainly Syria, Afghanistan, and Iraq.

The UN agency is contributing to the efforts to address the urgent situation by providing interpretation services, legal information, and basic emergency assistance, as well as supplies of water, and sleeping bags and hygiene kits, according to the spokesman.

The reception infrastructure, services and registration procedures are falling far short of real needs, the UN agency said.

"Such a level of suffering should and can be avoided," said Vincent Cochetel, UNHCR's director of the Bureau for Europe, who last week visited Greece with the director of emergency, security and supply to assess the refugee crisis.

"The Greek authorities need to urgently designate a single body to coordinate response and set up an adequate humanitarian assistance mechanism," Cochetel said. "As Greece faces financial challenges, the country needs help, European countries should support Greece on these efforts."

So far in 2015, more than 225,000 refugees and migrants have arrived by sea in the Mediterranean and around 2,100 are estimated to have died or gone missing while trying to reach Europe, not including the incident that took place earlier this week when an overcrowded fishing boat sank off the coast of Libya.