US President Donald Trump threatened on Monday to block sales of Canadian planemaker Bombardier in the United States unless it builds aircraft in the country, escalating trade tensions on the eve of Canadian retaliatory tariffs. The threat comes a day before Canada’s retaliatory tariffs on about C$27.6 billion worth of US imports take effect on Tuesday, September 8. Key points and original sources are listed below.

• US President Donald Trump threatened on Monday to block sales of Canadian planemaker Bombardier in the United States unless it builds aircraft in the country, escalating trade tensions on the eve of Canadian retaliatory tariffs. Trump accused Canada of “unjust...S1

• The threat comes a day before Canada’s retaliatory tariffs on about C$27.6 billion worth of US imports take effect on Tuesday, September 8.S2