Turkish President Tayyip Erdogan poses with children during a ceremony to mark the National Sovereignty and Children's Day at the Presidential Palace in Ankara, Turkey, April 23, 2017. Murat Cetinmuhurdar/Presidential Palace/Handout via REUTERS

BRUSSELS (Reuters) - The European Union executive urged EU governments on Monday to consider changing its relationship with Turkey after a referendum that handed President Tayyip Erdogan sweeping powers put Ankara’s stalled membership talks deeper into cold storage.

Enlargement Commissioner Johannes Hahn, who is responsible for negotiations with countries wanting to join the bloc, called on EU foreign ministers when they meet in Malta on Friday to consider a new format for relations with Turkey, one that could ease mutual frustrations and reinforce cooperation.

“The current situation is not sustainable,” Hahn said.

He added that he did not want to prejudge discussions among the member states on whether they should suspend Turkey’s accession request, which they accepted in 2005. Hahn’s native Austria has been among the most prominent advocates of a freeze.

Some other states fear that could see Turkey act on threats to end a year-old agreement which has stemmed the flow of migrants to Greece and on to Germany. However, many in the EU believe Ankara has good reasons, including the financial aid that is part of the deal, not to stop cooperating on migration.

The European Commission and its member states have grown increasingly skeptical of Turkey’s accession process as Erdogan has cracked down on opponents and sought to increase his power. Turkey also questions the value of a process which few in Europe have seen leading to membership in the foreseeable future.

Hahn said he shared the concerns of the Council of Europe, the continent’s human rights body, which said Erdogan’s constitutional changes were a “dangerous step backwards” for Turkish democracy. But he said the European Union could look at reinforcing cooperation with Turkey in areas other than EU membership that could benefit both sides.

The Commission has been looking at updating its customs union arrangements with Ankara. Hahn stressed that whatever relationship the EU might have with Turkey, including economic ones, its respect for the rule of law would remain crucial.