EU executive to present steps to tighten external border controls

More than 160 people were killed in the November shooting and bombing attacks in Paris and suicide bombings in Brussels in March. The deadly strikes, claimed by Islamic State, strengthened the hand of those campaigning for tighter security checks and data sharing against those who warn of the risks of abuse and undermining privacy through enhanced surveillance.

In its proposal on Wednesday, seen by Reuters ahead of official publication, the European Commission said the carnage in Paris and Brussels "brought into sharper focus the need to join up and strengthen the EU's border management, migration and security cooperation."

Europol chief Rob Wainwright highlighted separately on Tuesday an "indirect link" between Europe's migration crisis, which saw more than a million people arriving over the last year, and the Islamist militant threat, saying some militants had used the chaotic migrant influx to sneak in.

EU border agency Frontex also said that two of the perpetrators of the Nov. 13 attacks in Paris had entered through Greece and been registered by Greek authorities after presenting fraudulent Syrian documents.

"EU citizens are known to have crossed the external border to travel to (Middle East) conflict zones for terrorist purposes and pose a risk upon their return. There is evidence that terrorists have used routes of irregular migration to enter the EU," the Commission said in its proposal.

But the EU has a dozen-or-so different sets of fragmented databases for border management and law enforcement that are plagued with gaps and often not inter-operable. Custom authorities' data are held largely separate.

The Commission on Wednesday will therefore set out technical proposals to beef them up and improve the way they communicate with one another, including a joint search interface.

Although not a new idea in general, doing this requires complex measures that pose a host of technical and legal challenges in balancing the need for data and privacy protection with enhanced security.

The Commission also revised a proposal, first made in 2013, for an "Entry-Exit" system for third-country nationals arriving in the EU to "reduce irregular migration by addressing the phenomenon of overstaying and contribute to the fight against terrorism and serious crime".

Under the outline, the new system would be implemented by 2020 to register data of non-EU nationals arriving from outside the bloc, including four fingerprints and a face image.

Scores of Europeans have ventured out to join the ranks of Islamic State and some have come back to the 28-nation EU, including those involved in the Paris attacks.

That stirred discussion on the need to also tighten controls of EU citizens on external borders, but this angle was not included in the Commission's document on Wednesday.

Also mentioned was the so-called PNR - an EU deal on sharing detailed air passenger data that has seen months of wrangling. The Commission said it should be adopted "in the coming weeks" and is crucial in efforts to increase security.