Schengen countries apply common external border controls, a common visa policy and share a police database on criminals and lost cars.
Checks will continue at airports for intra-Schengen flights until the end of March 2008.
Thirteen EU countries, plus Norway and Iceland, are currently part of the Schengen area whose members dismantle internal border posts.
Britain and Ireland have chosen not to join.
The nine countries that will join "Schengen-land" in December all became members of the now 27-nation EU in 2004.
Cyprus, which joined at the same time, has asked for one year's delay.
Romania and Bulgaria, which joined the EU only this year, need to do more work to meet security criteria, officials have said.
"It's not only for travelling," Mate said. "I strongly believe ... in local areas the economy will start growing better and better, and usually the areas around borders are not well developed.
"They will now have a new push."