EU President Donald Tusk has warned that the refugee crisis affecting Europe was part of an "exodus" from war-torn countries that could last years.
Speaking to the Bruegel Institute think-tank in Brussels on Monday, Tusk said the current movement of people mainly from the Middle East would be a "problem for many years to come".
"The present wave of migration is not a one-time incident but the beginning of a real exodus," Tusk said.
European leaders are scrambling for solutions as bloody conflicts in mainly Syria and Iraq send hundreds of thousands of refugees on dangerous voyages through the Balkans and across the Mediterranean to the 28-nation EU.
"Let us have no illusions that we have a silver bullet to reverse the situation," he said.
Tusk, who represents the bloc's leaders, urged for pragmatism and said member states must put aside their deep differences in facing the crisis.
"Also, we should not feel ashamed of our emotions," Tusk said, just days after an image of a refugee toddler drowned on a beach in Turkey shocked the world.
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One of the flashpoints of the crisis is Hungary, where tens of thousands of refugees seek to transit through on their way to wealthier EU states.
On Monday night, hundreds of angry and frustrated asylum seekers broke through police lines near Hungary's southern border with Serbia and began marching north towards Budapest.
Crowds who had grown tired of waiting for buses at Hungary's first refugee holding centre near the border village of Roszke on Monday tore down flimsy police tape, advanced down a country road and walked around rows of police trying to block them.
Officers offered no resistance as about half of the 500-strong crowd reached the M5 highway that connects Serbia and Hungary.
They headed north along the shoulder, raising their arms and chanting "Germany! Germany!"
Al Jazeera's Andrew Simmons, reporting from Roszke in Hungary, spoke to several refugees who said they had been poorly treated and did not have access to adequate shelter or sanitation.
"It's getting worse, hundreds of refugees have spent three days living in this field, guarded by police, waiting to be registered," Simmons said.
One refugee said she had been beaten with a stick, while another pleaded with authorities to help her sick child.
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The five-year-old, who was suffering from heat exhaustion and fever, was eventually helped by Hungarian medical teams and put on a drip, Simmons said.
Hungary's Defence Minister Csaba Hende resigned after a national security council meeting was held to discuss the influx of refugees on Monday.
Prime Minister Viktor Orban has pushed for a hardline on Europe's refugee crisis.
Fresh clashes also erupted between police and refugees on the Greek island of Lesbos Monday night, which authorities said was "on the verge of explosion".
A dozen or so coastguard personnel and riot police armed with batons struggled to control some 2,500 refugees on the island, screaming "Keep back" at the crowds as they surged towards a government-chartered ship bound for Athens.
A number of European countries have announced they will be taking in part of the influx of people wanting to escape the conflicts in the Middle East.
British Prime Minister David Cameron said his country would resettle up to 20,000 Syrians from camps in Turkey, Jordan, and Syria over the next five years.
French President Francois Hollande said his country would take in 24,000 refugees over the next two years.
The United States government said it was considering a range of approaches in response to the global refugee crisis including with regard to refugee resettlement.
|EU states are divided on a quota system, which allocates refugees to different member countries [AP]
Source: Al Jazeera and agencies