A plan by the European Union and Turkey aimed at tackling migration flows came under fierce criticism from human rights advocates on Tuesday, even as thousands of asylum seekers remained stranded in Greece.

Europe has struggled with an influx of migrants and asylum seekers that brought more than 1 million people to its shores last year, with some 140,000 more following since January. Many are fleeing the war in Syria, but economic migrants have also joined their ranks.

Late Monday, EU leaders and Turkish Prime Minister Ahmet Davutoglu agreed to work on a deal under which all migrants reaching Greece from Turkey would be returned to the country, while the EU would directly resettle as many Syrians from Turkey as Ankara took back from Greece.

The aim is to discourage people from taking illegal migration routes into Europe and convince them to apply for asylum from Turkey instead.

Discussions on the new framework continued Tuesday, when Davutoglu and his Greek counterpart, Alexis Tsipras, met in the Turkish coastal city of Izmir.

"Turkey will take back the refugees," Davutoglu said after the meeting. "But in exchange the EU will take the same number of refugees."

Davutoglu also stipulated that visa requirements for Turks also be lifted for the Schengen area, but no final agreement has been reached with the EU over the Turkish premier's requests.

EU officials hope to hash out details of the plan - which includes many legal uncertainties - in time for their next summit, on March 17-18.

But the proposal - under which Turkey can also expect new EU funding and progress in its long-running bid to join the bloc - was described as inhumane and potentially illegal by human rights organizations.

"EU and Turkish leaders have today sunk to a new low, effectively horse-trading away the rights and dignity of some of the world's most vulnerable people," said Iverna McGowan of Amnesty International.

"I am deeply concerned about any arrangement that would involve the blanket return of anyone from one country to another without spelling out the refugee protection safeguards under international law," added UN High Commissioner for Refugees (UNHCR) Filippo Grandi, in a speech to the European Parliament.

UNHCR's Europe regional chief Vincent Cochetel went further, stating that "collective expulsion is prohibited." Sending back all migrants, paying Turkey more money and easing EU entry policies for Turks would not provide a quick fix to the problem, he added.

After arriving in Greece, most migrants have tried to reach northern Europe via the Balkans. But thousands are now stranded in Greece, after countries further north instituted border restrictions.

In the Idomeni refugee camp, on the Macedonian border, heavy rainfall has turned the ground to mud and left tents waterlogged. The camp, which was set up for 2,000 people, now holds more than 13,000 who cannot move on. Many have been waiting for more than three weeks.

The crush of people was also felt further north. A refugee from Iraq told dpa by phone that he and a group of others had been stranded on Macedonia's border with Serbia since Friday morning, apparently as authorities there await a clear signal from the EU about the way ahead for migration policy.

The bloc's leaders fell short Monday of declaring the Western Balkan migration route "closed," as countries on the pathway between Greece and northern Europe had demanded. But their joint statement said that irregular migrant flows along the route "have now come to an end."

But the surge into Greece from the south continued Tuesday, with more migrants and asylum seekers arriving on the mainland by ferry after making the dangerous Aegean Sea crossing from Turkey.

Around 1,000 people were expected to disembark Tuesday in Athens' port of Piraeus and to continue north, toward Idomeni.

Latest news

Syrian opposition rules out future role for President al-Assad

The Syrian opposition said Friday it would not accept any role for President Bashar al-Assad in the future of the war-torn country, reacting to a recent US shift saying that removing al-Assad is no longer a priority for Washington.

Russian Army integrates breakaway forces of Georgian province

Parts of the small fighting forces of the Georgian breakaway province of South Ossetia have been placed under Russian military control, Russian Defence Minister Sergei Shoigu said on Friday.

Czech Republic's Pilsner Urquell beer is now Japanese

Japanese brewing company Asahi completed its takeover of the Czech brewery Pilsner Urquell on Friday, Asahi said in a statement.

Judge approves 25-million-dollar settlement of Trump University case

A US district judge on Friday approved a 25-million-dollar settlement of lawsuits and state fraud allegations against Trump University, the US president's now-defunct business venture.

Former Thai premier Thaksin to junta on reconciliation: 'Cut me out'

Former Thai prime minister Thaksin Shinawatra on Friday announced that he is not interested in the junta-led reconciliation process, three days after the junta handed him a half-a-billion-dollar tax bill for his past business deal.

Dalic: We welcome possible deal between Agrokor and banks

The government welcomes the possibility of an agreement being concluded between the Agrokor food company and creditor banks, and the bill on vitally important companies is not a fallback plan but the result of the government's care for the overall economic and financial stability of Croatia, Deputy Prime Minister and Minister of Economy Martina Dalic told a press conference in Zagreb on Friday.

Croatia, China sign action plan for cooperation in agriculture

The Croatian and Chinese ministries of agriculture on Friday signed an action plan for cooperation in the field of agriculture for the period 2017-2018, the Croatian ministry said in a statement.

ZSE indices up, Agrokor shares in focus of investor interest

The Zagreb Stock Exchange (ZSE) indices on Friday rose by more than 1.8%, with stocks of the Agrokor food and retail concern being in the focus of investor interest again.

Berlin police defend handling of Berlin market attacker

Berlin police defended themselves on Friday against accusations that they stopped surveillance on Berlin Christmas market attacker despite knowing in June 2016 he was dangerous.

Croatia, creditors tailor emergency measures to save tottering giant

Croatia's tottering retail and food giant Agrokor reached an agreement with its creditors, putting its debts standby and allowing it to continue working during emergency restructuring, the Croatian branch of Austria's Erste Bank said Friday.

Agrokor's creditors say standstill agreement to go into force today

A standstill agreement regarding the Agrokor concern's existing financial obligations to banks will take effect on Friday, additional capital will be injected into the concern in the coming days and the concern will be actively restructured, which includes a change of its management, it was said on Friday after a meeting between Agrokor's suppliers and creditor banks.

Palestinians, UN slam Israel's new settlement plan

Palestinians, Israeli activists and the UN lambasted the government of Israeli Prime Minister Benjamin Netanyahu on Friday, a day after it gave the go-ahead for the first new West Bank settlement in a quarter of a century.

South Sudan rebels release three abducted foreign oil workers

South Sudanese rebels have released three foreign engineers they abducted in early March in the oil-rich Upper Nile region, Foreign Affairs Ministry official Mawein Makol Arik said on Friday.

Turkish opposition: Imprisoned party chief has gone on hunger strike

The head of Turkey's pro-Kurdish opposition party has launched a hunger strike from prison.

European leagues threaten Champions League schedule clashes

The European Professional Football Leagues (EPFL) on Friday threatened schedule clashes on Champions League matchdays in an ongoing dispute with the governing body UEFA.

Danish court revokes citizenship of IS volunteer

A Danish appellate court on Friday stripped a man of his Danish citizenship for volunteering to fight for the extremist Islamic State in Syria.

Banks and Agrokor agree on key elements of standstill agreement

Member banks of the coordinating committee of financial creditors and representatives of the Agrokor food company have in principle agreed on key elements of a standstill agreement, which is expected to be signed later today, announcing changes in the company's management team, Erste Bank said in a statement on Friday afternoon.

Syrian man on trial in Sweden; mosque attack labelled terrorism

A Syrian man went on trial Friday in the southern Swedish city of Malmo, charged with terrorism and arson after an attack last year on a building used as an assembly hall by Shiite Muslims.