Link to a post in an earlier thread showing the statement is from Sean Spicer-The White House.
IT IS OFFICIAL AND REAL NEWS, NOT FAKE NEWS......
http://www.freerepublic.com/focus/f-news/3564389/posts?page=39#39
Trump is letting the Russians and Syria know ahead of time. If Assad uses chemical weapons then Russia will know ahead of time and their will be no excuses.