European Commission spokeswoman Mina Andreeva said on Monday that the Commission would adopt a report on Croatia's compliance with the Schengen Area requirements on Tuesday.

Tomorrow the College of Commissioners will evaluate Croatia’s progress in meeting the criteria required for joining the Schengen Area, she said after the chiefs-of-staff of all commissioners defined the agenda of Tuesday’s Commission meeting in Strasbourg.

Numerous prerequisites must be met to join the passport-free travel area, including taking responsibility for controlling the EU’s external borders, issuing Schengen visas on behalf of the area’s other member states, and establishing efficient cooperation with the security authorities of the member states.

A country hoping to join must be capable of fully enforcing the Schengen Borders Code, which includes controlling the borders on land, at sea and in airports, issuing visas, police cooperation and personal data protection. The country must also be entered into the Schengen Information System.

The Commission carries out an evaluation before a country enters the Schengen Area, as well as occasionally after accession to see if the Schengen laws are being enforced. The Commission’s evaluation on technical preparedness is not enough for joining but it is a prerequisite for the member states to make a political decision on the accession.

Bulgaria and Romania, for instance, have had a positive evaluation since 2011 but have still not joined Schengen because there is no consensus among the member states.

Croatian Prime Minister Andrej Plenkovic said in late September that it was difficult to predict when Croatia would join Schengen but that the goal was to receive a positive evaluation by the Commission this year that Croatia had met all the criteria.