Fifteen EU states called for “new ways” to handle irregular migrants, including sending some to third countries, in a letter to the European Commission.
The member states made the demand as the bloc examines how to carry out a recently adopted overhaul of its asylum rules.
The push comes less than a month before European Parliament elections across the 27-nation EU, in which far-right anti-immigration parties are expected to make gains.
Austria, Bulgaria, Cyprus, the Czech Republic, Denmark, Finland, Estonia, Greece, Italy, Latvia, Lithuania, Malta, the Netherlands, Poland and Romania signed the letter.
In it, they ask the EU's executive arm to “propose new ways and solutions to prevent irregular migration to Europe”.
They want the bloc to toughen its asylum and migration pact, which introduces tighter border controls and seeks to expedite the deportation of asylum seekers whose applications were rejected.
The pact, to be operational from 2026, will speed up the vetting process for people arriving without documents and will also establish new border detention centres.
The 15 countries also want to see mechanisms to detect and intercept migrant boats and take them “to a predetermined place of safety in a partner country outside the EU, where durable solutions for those migrants could be found”.
They said it should be easier to send asylum seekers to third countries while their requests for protection are assessed.
They cited as a model a controversial deal Italy has struck with Albania, under which thousands of asylum seekers picked up at sea can be taken to holding camps in the non-EU Balkan country as their cases are processed.
Migrants arriving in Europe – in pictures
The European Commission said it would study the letter, although spokeswoman Anitta Hipper added that “all our work and focus is set now on the implementation” of the migration and asylum pact.
EU law says people entering the bloc without documents can be sent to an outside country where they could have requested asylum – so long as that country is deemed safe and the applicant has a genuine link with it.
That condition differentiates it from a scheme set up by non-EU Britain under which irregular arrivals will be denied the right to request asylum in the UK and will be sent instead to Rwanda.
The 15 nations said they want the EU to make deals with third countries along main migration routes, citing the example of the arrangement it made with Turkey in 2016 to take in Syrian refugees fleeing war.
“In legal terms, these models pose many questions and are very costly in terms of resource mobilisation and at the operational level,” said Camille Le Coz, associate director of the Migration Policy Institute think tank.
The opening date for migrant reception centres in Albania set up under the deal with Italy had been delayed, she added.
With the June 6-9 EU elections leading to a new European Commission, the proposals put forward by the 15 countries would go into the inbox of the next commission for it to weigh them, she said.
She also noted that EU heavyweights France, Germany and Spain had not signed on to the letter.
“For certain member countries, the priority really is the implementation of the pact, and that in itself is already a huge task,” Ms Le Coz said.
Meanwhile, the incoming Dutch government led by nationalist Geert Wilders' PVV party will aim to pursue its curbs on immigration by opting out of EU migration rules, setting up a clash with Brussels before it has even taken office.
Mr Wilders won an election nearly six months ago and reached a deal on Wednesday to form a coalition with three right-wing partners. He has not yet proposed his choice for prime minister, but has ruled himself out.
In its government plan published early on Thursday, the four-party coalition says it will aim for the “strictest-ever asylum regime” with stronger border controls and harsher rules for asylum seekers who arrive in the Netherlands.
“An opt out clause for European asylum and migration policies will be submitted as soon as possible to the European Commission,” the coalition says in its pact.
Mr Wilders said the plan would make the Netherlands less attractive for asylum seekers, adding that “people in Africa and the Middle East will start thinking they might be better off elsewhere”.
The Netherlands would join Hungary and Poland's previous nationalist government in challenging EU migration policy.
Brussels is likely to resist, as EU countries have already agreed on their migration pact and opt-outs are usually discussed in the negotiating phase.
The Dutch coalition parties said labour migration would also be curbed, and admittance of foreign students to Dutch universities will become stricter.
Workers from outside the EU who do not have specific knowledge or expertise would need a work permit and recruiting agencies will face stricter regulation.
The coalition says it would also strive to limit free movement for people from countries joining the EU in the future.
Tech industry association FME, representing firms including semiconductor industry powerhouse ASML, said it was concerned such measures would hamper hiring by tech companies.
