On December 21 2007, the Czech Republic, Estonia, Hungary, Latvia. Lithuania, Malta, Poland, Slovakia and Slovenia joined the Schengen Treaty.

Four-hundred million citizens can freely travel the new 24 country area.

According to Bulgarian Foreign Minister Ivaylo Kalfin, Bulgaria and Romania could join Schengen in 2010 or 2011.

"The realistic date for entering the Schengen Treaty zone is 2010 or 2011. But that depends on how prepared Romania will be, since it would be odd for Bulgaria to join, but to have a Schengen border with Romania," Kalfin said.

Since joining the EU in January 2007, the two countries have been preparing to join the Schengen Treaty.

Inspections would start in 2008 to see how prepared they were and were expected to last at least two years, Kalfin said.