OTTAWA -- The United Steelworkers union is urging Ottawa to immediately impose retaliatory tariffs on steel, aluminum and other imports from the United States instead of waiting until the end of the month, as it has proposed.

National director Ken Neumann says delays are a mistake as U.S. tariffs on Canadian steel and aluminum began June 1 and are already causing economic harm in Canada.

He says customers looking to buy products are making decisions now based on the current situation, which may disadvantage Canadian producers.

Prime Minister Justin Trudeau has rejected other calls to speed up the imposition of retaliatory tariffs, saying he wants to respect the government's 30-day consultation period on its proposed $16.6-billion tariff package.

The Trump administration's tariffs amount to 25 per cent import duties on steel and 10 per cent on aluminum.

Neumann said the steel industry should be offered support similar to Quebec's offer of $100 million in loan guarantees to support the aluminum industry there.

"Canada must immediately take steps to protect Canadian steel and aluminum imports from the diversion of cheap imports from the U.S. into Canada," he said.