BRUSSELS — Documents seen by The Associated Press show that European Union countries are poised to restrict passport-free travel by invoking an emergency rule for two years due to the migration crisis.

Each of the 26 countries in the open-travel Schengen Area is allowed to unilaterally put up border controls for a maximum of six months. That limit can be extended for up to two years if a member nation is found to be failing to protect its borders.

The documents show that EU policymakers are poised to declare that Greece is failing to sufficiently protect its border. Some 2,000 people are still arriving daily on Greek islands in smugglers’ boats from Turkey.

A European official showed the documents to the AP on condition of anonymity because the documents are confidential.

The EU nations said in a statement that there are “serious deficiencies” to how Greece is protecting its border, which also is an external border of the whole Schengen zone of passport-free travel, and urged Athens to address them.

More than 1 million migrants have entered the EU since the beginning of 2015 and most have come through Turkey and into Greece as they make their way up to European nations like Germany and Sweden.

Several nations have imposed temporary border controls to deal with the crisis and many have criticized Athens.