March 5 (Reuters) - Canadian Prime Minister Justin Trudeau called U.S. President Donald Trump on Monday about proposed steel and aluminum tariffs and "forcefully defended" Canadian workers and the industry, a government official said.

The official, who spoke on the condition they not be named, said the two leaders had a constructive conversation. Canada has threatened to retaliate if Trump goes ahead this week and imposes the tariffs. (Reporting by David Ljunggren Editing by Chris Reese)