After a couple of inspections, umpires Nigel Llong and Ian Gould decided to call off the game at 3:46pm.
The sky was still cloudy when the final inspection was held, keeping in mind a 20-over-a-side game.
Both Pakistan and Sri Lanka have won one and lost one match each.
Pakistan lost to West Indies by seven wickets in their opening match before beating favourites England by 14 runs.
Sri Lanka, on the other hand, lost to New Zealand by 10 wickets and brought their campaign back on track with a 34-run victory (DLS) against Afghanistan.