Under amended EU regulation, travel documents of all passengers, including those enjoying the right of free movement, will have to be checked against relevant databases on all external EU borders.

Such systematic border checks are now only conducted on third-country nationals. As of 7 April they will be expanded to EU nationals and their family members.

Addressing a press conference in Ljubljana, border police official Robert More said that no exceptions were planned, even during the summer tourist season.

"Every passenger will be checked against the databases [Schengen Information System, Interpol databases and national databases] and if the travel documents are OK will continue their journey," said More, adding the procedure for EU citizens should not take more than a few seconds.

The measure is expected to increase waiting times at the border, but police will seek to alleviate the problem through organisational adjustments by securing extra staff as needed and opening extra lanes.

During the summer season, police will be continuously monitoring traffic flows, issue notifications on congestions and divert passengers to less busy crossings.

Everyone travelling across external border is advised to check in time whether they have valid travel documents on them.

Robert More said the police force had sufficient resources and expected no technical problems considering that all border crossings are fitted to Schengen standards.

For the time being no staff reinforcements or extra funding are planned, but the situation will be monitored and potential measures taken in response to the situation on the ground.

The goal of systematic checks is to detect falsified or forged travel documents and EU nationals involved in armed conflicts in the Middle East and the broader region.