De Silva and Davis have already been serving on the Emirates International Panel of ICC umpires.
The ICC Umpires Selection Panel made up of David Richardson, ICC's General Manager Cricket, ICC chief match referee Ranjan Madugalle, ex-England player, coach and former first-class umpire David Lloyd and S Venkataraghavan, the former India captain and international umpire.
After making his debut in 1999, De Silva has stood in 33 Tests and 76 ODIs and has served previously on the Elite Panel between 2002 and 2004. The 52-year-old also played 10 Tests and 28 ODIs for Sri Lanka between 1985 and 1992.
Davis, 56, has stood in 11 Tests, 71 ODIs and three T20 Internationals having made his top level debut in 1992. He has been a member of the International Panel since 2003.
Richardson said, ''We are delighted to confirm the elevation of both Steve and Asoka to the expanded Emirates Elite panel of ICC Umpires.
''Their promotions are a result of perseverance, hard work and commitment and I am sure these two umpires will serve as an inspiration to the other Emirates International Panel umpires who are striving hard to break into the Elite Panel,'' he said.
Top level umpires will be assisted by five regional umpire managers who will work with those umpires to ensure peak performance. The remuneration of officials at the highest level has also been improved to reflect their value to the game.
These developments followed recommendations made by an ICC Umpiring Task Force made up of Chairman David Morgan, the ICC President-Elect, ICC Chief Match Referee Ranjan Madugalle, Cricket Australia manager Geoff Allardice and Richardson.