European Union interior ministers have agreed to deliver more quickly on their promises for tackling the migration crisis as their host called for averting a humanitarian catastrophe with winter approaching.

The extraordinary meeting on Monday came ahead of a special EU-Africa summit in Malta on Wednesday, focused on how to reduce the flow via Libya, the second-busiest migrant route after Turkey and the Balkans.

EU member states have come under fire from the commission, the 28-nation bloc’s executive, for taking too long to act on pledges to tighten external borders, set up centres to process migrants, and relocate asylum seekers from overstretched Italy and Greece.

But their interior ministers pledged to move faster on those fronts as well as accelerate the building of shelters up through the western Balkans route from Greece, where migrants land after the dangerous sea crossing from Turkey.

“The European Union has to do everything it can to avoid a humanitarian catastrophe as winter approaches,” Jean Asselborn, the Luxem-bourg immigration minister, told a closing press conference. “We have to try to save people at sea... And we can’t allow people to die of cold in the Balkans,” said Mr Asselborn, the host of the meeting.

Meanwhile, Slovenia on Tuesday outlined plans to build “obstacles”, potentially including fences, on its border with Croatia, as it braced for a new spike in migrants bound for northern Europe this week. Prime Minister Miro Cerar, whose country in October found itself on the main Balkans route for thousands of migrants, insisted however that its frontier would remain open. “We decided yesterday to start building over the following days on the Schengen (zone) border with Croatia some temporary technical obstacles,” Mr Cerar said.

German Chancellor Angela Merkel urged the EU to secure its external frontiers, saying this could have saved Slovenia from tightening its border.

The situation in Slovenia underlines “the urgency with which we have to work towards a common European solution, and that means securing the external borders,” said Ms Merkel.