LISBON, Portugal (AP) — Portugal started consultations Tuesday with other European Union countries to find common ground for a new policy on migration, which has caused humanitarian crises and deep political divisions in the bloc over how to respond.

Portugal, which holds the EU’s rotating presidency for the first half of this year, is working on a concept of “flexible, mandatory solidarity” between countries, according to a statement from the office of Portuguese Home Affairs Minister Eduardo Cabrita.

Defining what that concept entails is Portugal’s goal for a meeting of EU justice and home affairs ministers on Jan. 28, the statement said.

But migration from outside the EU requires the bloc’s members to stand together, and “solidarity cannot be voluntary,” the statement said.

“The main goal must be to avoid having people who are searching for a better life in Europe remain for long periods of time in temporary accommodation ... without any clarification about their future,” it said.

Cabrita spoke Tuesday to Greece’s minister for migration and asylum. He plans to speak to officials in other southern European countries which have taken in large numbers of migrants, as well as to authorities in central and eastern European countries where migrants have often been made to feel unwelcome.

Finding consensus for a common EU policy on migration has eluded the bloc for years.

Portugal also wants to reach a comprehensive migration agreement with countries along the Mediterranean Sea’s southern rim, from where many migrants cross to the EU. That should include not only tight border controls, but also rules on legal migration and development aid, the statement said.

Legal migration can help some EU countries find answers to low birth rates and aging populations, it said.