President Trump's threat, posted in the early hours Thursday on his social media network, is the latest way he has sought to use his trade war to coerce countries on unrelated issues and is a swing from the ambivalence he has expressed about other countries making such a move.

Trump said it would be “very hard” to reach a deal with Canada after the country said it plans to recognize a Palestinian state in September.

OTTAWA — Canada plans to recognize a Palestinian state at the UN General Assembly in September, Prime Minister Mark Carney said Wednesday, a major policy shift that drew an angry response from United States President Donald Trump and was rejected by Israel.