A final evaluation of whether the security standards are met will be made starting in mid-2007 by the EU's executive Commission.
Malta, Poland, Hungary, the Czech Republic, Estonia, Latvia, Lithuania, Slovakia and Slovenia have all applied for full entry into the Schengen zone, while Cyprus opted to keep in place some of its border checks.
Discussions have continued for over a year and some of the eastern European countries have suggested the issue was delayed by older member states keen on preventing an eastward expansion of the Union's passport-free zone.
Earlier, Britain and Ireland's concerns over cost had threatened to bring an end to discussions.
Langer said a deal was reached after the 10 new member states agreed to pay Britain's and Ireland's share for allowing the new countries to join the visa-data system.
The schengen treaty
EU members: Austria, Belgium, Denmark, Finland, France, Germany, Italy, Greece, Luxembourg, the Netherlands, Portugal, Spain, Sweden
Non-EU members: Iceland, Norway
Under the compromise plan, the 10 nations to join the Schengen visa area would be temporarily allowed to link into the current visa data system, which will be adapted to accommodate them until the updated version is launched in June 2008.
Wolfgang Schaeuble, Germany's interior minister, said there would be a six-month test phase of the adapted computer system in June.
He said: "We have to check the real level of controls and protection of the external borders."
Britain and Ireland are not part of the Schengen zone, but still pay for the running of the system, which currently costs around EUR25 million ($33m) a year.
Adding the new members would cost up to an additional EUR6 million ($8m).
The schengen treaty currently covers all the oldest EU countries, except Britain and Ireland, plus non-EU nations Norway and Iceland.