Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Slovenia, Slovakia and the Czech Republic - which all joined the EU in 2004 - are part of this latest enlargement.

Checks at internal land and sea borders will be abolished on 21 December, with air borders to follow in March 2008.

"With [Thurday's] decision, the last barrier to our full EU membership will fall", Slovakia's deputy prime minister Dusan Caplovic said on Monday (5 December), adding that it is time for the 'old versus new' divide in Europe to come to an end.

The Schengen area - established in 1985 in a small Luxembourg village at the geographical meeting-point of Germany, the Benelux countries and France - currently consists of thirteen EU states, plus Norway and Iceland.

The UK and Ireland have chosen to stay out and participate only partially in police and judicial cooperation. Bulgaria, Cyprus and Romania are yet to meet necessary requirements, while Switzerland is expected to fully take part in Schengen in the coming months.

According to commissioner Frattini, the enlargement of the Schengen area will not mean the reduction of security, as 58 monitoring missions were carried on the ground in 2006 and additional fifteen re-evaluations in 2007.

The EU's external borders are "secure and safe", he said, adding "I, as an Italian, will consider the Polish-Ukrainian border to be my border".

Brussels to tighten evaluation

Originally, the Schengen area was supposed to be enlarged by October this year, but the move had to be postponed due to technical problems surrounding the installation of a new central database, known as the SIS II.

The database - the updated version of the existing system - is considered the technical soul of Schengen, as it connects member states' national databases on all kinds of information related to border security, such as stolen documents, cars or firearms.

After pressure from the nine Schengen-hopefuls, who suspected political motives for the delay, the Portuguese EU presidency tabled a compromise, known as SIS one 4 all, suggesting that the newcomers join the existing database (SIS I).

"Sometimes Europe is able to make progress in a very short time", commissioner Frattini said, adding that the new information system, SIS II, should be up and running on 18 December 2008.

Around the same time, the EU's executive body is set to propose changing the way how the member states' performance in the area is evaluated.

"Currently, you have to knock on the door and only then carry out an evaluation", one EU official said, adding that Brussels aims at changing "announced" missions for "unannounced" ones.

But EU capitals will not lose the power to decide where and how often to carry out such check-ups.