European Union envoys agreed on a new set of demands for Greece to fix deficiencies with its external border management concerning irregular refugees on Wednesday.
Brussels has raised the possibility of a two-year suspension of border controls in the passport-free Schengen travel area if Greece does not bring its response up to the desired level.
According to EU diplomatic sources, a meeting of ambassadors from the Union's 28-member states approved a second set of recommendations to Greece. The Commission adopted the Schengen Evaluation Report on Greece and proposed recommendations on February 2.
Greece has been asked to end deficiencies in controlling its part of the Schengen area external border within three months.
If Greece fails to implement all the measures, an unprecedented measure under the Schengen treaty would allow states in the Schengen area to impose checks on their own borders for up to six months. The measure would be renewable three times.
The European Commission said on Wednesday that returning to internal border controls on a systematic and long-term basis could cost as much as 18 billion euros ($20.15 billion) in total direct costs alone, excluding second-wave effects.
In an effort to at least maintain the structure within its legal framework, EU officials and diplomats are working to give governments a legal right to extend temporary internal border checks. Germany and France have already started in response to the worsening refugee crisis.
The legal basis for some of these expires in mid-May and so the EU has begun a process to trigger an unprecedented use of a longer-term derogation within the Schengen treaty by that time.
Another EU summit will be held next week in which European leaders will again discuss how to resolve the crisis that has set them against each other.