The EU said Thursday it was discussing plans with UN agencies to set up migrant processing centres outside the bloc, but insisted it would not create a "Guantanamo Bay for migrants".
The European Commission, the bloc's executive arm, said it envisaged deals with north African and other countries that fully protect migrants rescued at sea.
The proposal will be debated at next week's EU summit in Brussels.
"I want to be very clear on that. I'm against a Guantanamo Bay for migrants," EU Migration Commissioner Dimitris Avramopoulos told a news briefing. "This is something that is against our European values."
Washington triggered global outrage when it began using the US naval base in Guantanamo Bay Cuba to hold terror suspects in harsh conditions after the September 11, 2001 attacks.
"We are exploring together with the IOM and the UNHCR how can we further engage northern African countries in discussions on possibilities for regional disembarkation schemes," Avramopoulos said.
The EU is already working with the International Organization for Migration and the UN High Commissioner for Refugees to help migrants in detention centres in Libya return to their countries in sub-Saharan Africa.
Avramopoulos said the UN agencies would ensure that genuine refugees fleeing war or persecution can settle in Europe while economic migrants are returned home in dignity and with enough resources to restart their lives.
In addition to north African countries like Tunisia, Brussels is also considering non-EU countries in Europe like Albania.
But Avramopoulos said "no expression of willingness" has come from a potential host country because the EU is still discussing how the centres will work and has made no formal proposal.
"The way I see this is as an agreement of countries around the Mediterranean to ensure the people get the protection they need and are treated with the dignity they deserve," the Greek commissioner said.
"But it must also mean that getting on the boat does not mean a free ride to the European Union," he said.
The EU would make sure the proposed centres are housed in safe places, he said.
EU leaders are to discuss the centres at their June 28-29 summit as the bloc seeks to bolster its external borders.
A mini-summit is scheduled for Sunday to try to break the deadlock over reforming the so-called Dublin asylum rules that stipulate migrants must be processed in the EU country where they first arrive.
Countries like Italy and Greece complain they have unfairly had to shoulder the burden since the EU was hit in 2015 by its worst migration crisis since World War II.
Avramopoulos accused member states of failing to honour their commitments to a fund for Africa designed to tackle the poverty and other causes driving migration.
With the EU budget contributing 2.98 billion euros to the fund, a gap of 1.2 billion remains, he said.
He added that the EU will contribute another 145 million euros and urged member states to pledge at least 500 million euros to fill the gap "as soon as possible."
He also faulted them for not contributing enough personnel and equipment to the EU border guards force which he said will become a "genuine borders police" with 10,000 guards in the next few years.