After U.S. President Donald Trump announced a proposal to slap hefty tariffs on steel and aluminum imports, Finance Minister Bill Morneau says Canada is ready to retaliate if necessary.

鈥淐anada is an integral part of the supply chain on steel and aluminum in North America,鈥 Morneau told CTV Question Period host Evan Solomon.

鈥淲e clearly have said that this is important to maintain the ability for us to trade back and forth鈥 And obviously we鈥檙e going to be firm. We鈥檙e going to say that this is not an acceptable possibility for us to put tariffs on an important commodity like steel and aluminum.鈥

Trump announced the proposed tariffs on Thursday, outlining a 25 per cent tariff on imported steel and a 10 per cent tariff on imported aluminum. Canada is the top supplier of both metals to the U.S., with $15 billion a year in combined sales.

Morneau said the Liberal government鈥檚 first approach is to make its position on the issue known. If that fails to sway the Trump administration, Morneau added, 鈥淲e鈥檝e clearly said that we鈥檙e prepared to react.鈥

鈥淚 spoke to Treasury Secretary (Steven) Mnuchin this week to give him our point of view,鈥 Morneau explained. 鈥淗e clearly understood. So we鈥檙e going to keep working to make sure that all of the people that are involved in this decision get to what we hope will be the right answer.鈥

Morneau offered no specifics regarding potential retaliatory trade measures. He also rejected the U.S. government鈥檚 national security rationale for imposing tariffs, saying that they would 鈥渉arm鈥 both Americans and American businesses.

鈥淲e鈥檙e going to remind them that we don鈥檛 think a trade war is in anyone鈥檚 best interests, and we don鈥檛 want to be forced to react, but of course we will if we have to,鈥 he added. 鈥淲e鈥檙e working to make sure we get to the right conclusion, which is to exempt Canada from this action.鈥

Scheer cautions against retaliation

Conservative leader Andrew Scheer criticized the Liberal government for including nothing in their recent budget to buffer the effects of a potential trade war.

鈥淲e have a lot of difficulties right now with our trading partner and I believe that this government should be doing more,鈥 Scheer told CTV鈥檚 Question Period.

鈥淲e just saw in the budget not a single paragraph or fund or any type of signal that there would be a contingency plan if NAFTA goes off the rails or if these other trade irritants come along.鈥

The 2018 budget, Scheer added, 鈥渇ailed to treat these types of trade issues seriously鈥 and included nothing to make Canada 鈥渁 more attractive place to invest.鈥

Such measures, he said, could have come in the form of lower tax rates or regulatory reductions.

Scheer also said that he would have liked to see the government conduct more outreach to American companies that rely on Canadian trade in order to put pressure on the U.S. administration.

鈥淚f investors around the world and within the United States don鈥檛 see Canada as a place where they鈥檙e fighting to get into, then we have fewer voices in the United States putting pressure on the administration to keep that border open,鈥 he explained.

Scheer also cautioned against imposing retaliatory measures in the wake of potential steel and aluminum tariffs.

鈥淲e have to understand that any escalation in a trade fight also hurts our own economy,鈥 he said. 鈥淪o, as we slap tariffs on things that we import in from the U.S., that raises costs and damages our economy, so we have to be very careful. That鈥檚 not the preferred option.鈥

Watch Question Period Sunday mornings on CTV, 麻豆影视 Channel, CTVNews.ca, and 麻豆影视 GO at 11 a.m. ET, 10 a.m. CT, 9 a.m. MT and 8 a.m. PT