Authorities in Canada and the U.S. are investigating a death threat against America’s ambassador to Canada.

(Adrian Wyld/Canadian Press)

An expletive-filled letter and a suspicious ‘white powder’ substance were mailed to Kelly Knight Craft’s residence in Ottawa’s East End.

The powder has since been deemed NOT to be harmful.

Sources say the letter, believed to have been mailed from Quebec, threatened to kill the ambassador if she did not resign and also made threatening comments against Donald Trump.

Former U.S. Ambassador to Canada, Bruce Heyman, says while diplomats are threatened in ”troubled spots around the world,” he never was during his time in Ottawa from 2014-17.