EU commission backs Croatia's Schengen bid

"Once it [Croatia] becomes a full Schengen member, it will contribute to further strengthening the Schengen area and ensure that the EU's external borders are better protected," he added.

Croatia is one of six EU member states that is not part of Schengen, which comprises 22 EU countries and four other European ones - Iceland, Liechtenstein, Norway, and Switzerland.

The existing Schengen EU states must now decide unanimously on the zone's enlargement.

Commission president Jean-Claude Juncker promised in 2017 that Croatia would get in as soon as it met technical criteria.

He hoped "member states will take the right steps for Croatia to become a full Schengen member soon", he also said on Tuesday.

Schengen responsibilities include control of the EU's external borders, issuing Europe-wide visas, and cross-border law enforcement.

Croatia is up to the task, though it must pay special attention to its border with Bosnia, the commission's four-year long assessment said.

And the next commission chief, Ursula von der Leyen, also sees it joining by 2020, Croatia itself noted in a press release.

Its Schengen bid comes in turbulent times for EU enlargements after French president Emmanuel Macron vetoed opening new accession talks in the Western Balkans last week.

But Croatia's problem is more likely to revolve around its neighbour Slovenia than around France.

Slovenia once already blocked Croatia's bid over a territorial dispute.

Slovenia wants Croatia to accept the 2017 ruling of an arbitration tribunal in The Hague on their land and sea border in the northern Adriatic.

And earlier this month, Slovenian MEPs sent an open letter to EU leaders asking to postpone Croatia's accession once again.

"There are very serious reservations regarding Croatia's ... compliance with EU legal standards, notably regarding respect for and implementation of international agreements and judgments," the MEPs said.

For his part, Croatian prime minister Andrej Plenkovic said in September that "Slovenia can't block Croatia's Schengen entry indefinitely".

But for Slovenian foreign minister Miro Cerar, Croatia had to first bow to The Hague tribunal to show it was a "rule of law" state.

"Slovenia expects that in future Croatia will fulfill all the necessary conditions, both technical and legal, including respect for the rule of law, in order to enter into the Schengen area," said Slovenian prime minister Marjan Šarec.

Bulgaria, Croatia, Cyprus, and Romania are all meant to join Schengen one day under their EU treaties, while Ireland and the UK have opt-outs from membership.

"The doors [to join Schengen] will be open soon for Romania and Bulgaria," as well, Avramopoulos said on Tuesday.

Bulgaria and Romania have also had positive commission assessments, but have still not joined Schengen because some EU states harboured concerns on corruption in Sofia and Bucharest.

Meanwhile, the EU Council will be chaired by Croatia for six months from 1 January 2020, making it awkward to table a decision on the move early next year if Zagreb does not get in before then.