Bruce Heyman is stepping down as the top representative of the United States government in Canada.
The U.S. ambassador says he will leave the post effective Jan. 20, the day president-elect Donald Trump is to officially take office.
In a message on Twitter, Heyman makes clear he was asked to leave, saying he has resigned ``as requested.''
The New York Times reported this week that Trump's transition team has issued a blanket request that ambassadors appointed by President Barack Obama surrender their posts by inauguration day.
The Times said the order was delivered by a State Department cable just before Christmas.
Heyman has served as ambassador to Canada since being appointed by Obama in early 2014.