Foreign Affairs Minister Chrystia Freeland today praised all-party, pan-Canadian efforts to secure Canada a temporary exemption from Donald Trump's steel tariffs.

Reacting to the decision by the U.S. president to "hold off" on imposing the duties on Mexico and Canada, Freeland said politicians of all stripes, stakeholders and businesses worked energetically to reach a positive outcome.

"This has been a true Team Canada effort," she said during a news conference in Toronto today.

Freeland said "thorough, measured and effective" lobbying efforts will continue to protect Canadian industry and workers.

Trump has said the exemption is only guaranteed until Canada, Mexico and the United States conclude ongoing NAFTA trade talks.

But Freeland said the two issues — the tariffs and the trade talks — are on completely separate tracks, and that any move to slap Canada with tariffs on security grounds is "inconceivable." She said Canada is moving ahead in a spirit of goodwill and she's optimistic that NAFTA talks will reach a successful conclusion.

"We think a win-win-win outcome is absolutely possible," she said.

Conservative foreign affairs critic Erin O'Toole called the tariff exemption an "eleventh hour stay of execution," but said the last-minute scramble by the Liberal government to lobby U.S. officials highlights the fact that it dropped the ball on the file over the past several months.

"I'm happy with the outcome, but the prime minister's progressive agenda on trade has led to a deterioration of our relationship in Washington, because we're not seen as taking trade, or security, seriously," he said.

O'Toole, who travelled to Washington six weeks ago, said he heard complaints from U.S. officials that Liberal government representatives were not talking about security — but were pushing dwindling caribou herds as a priority issue.

He said the U.S. sees trade as inextricably linked to security, and Canada must deepen those ties if it wants to reap trade benefits — by signing on to a ballistic missile defence system, for example.

"We have to be a deep and full partner, and when the prime minister goes down and talks about his progressive agenda or caribou herds ... all of those things are important but they take a secondary priority to market access, to security," he said.

"They have to realize the administration they're dealing with has priorities and if Canada doesn't line our priorities up with theirs, we're going to pay a price."

NDP international trade critic Tracey Ramsey called today's announcement a "positive step for right now."

She said Canada's lobbying effort was a "full court press" with politicians from all parties, labour unions with international affiliations, stakeholders and producers.

"This has been a group effort at a grassroots level of just some intense education, I believe, about the Canadian component."

But Ramsey said Chinese dumping is a huge problem for Canada as well as the U.S., and the Liberal government needs policy to address it and strengthen the domestic industry.

Canada can't ease up on the lobbying efforts and must prepare for the possibility that the temporary exemption could end, she said.

An official in the Trump administration, speaking on background earlier today, said the tariffs of 25 per cent on steel and 10 per cent on aluminum will kick in 15 days from now.

But a decision on whether the exemption is permanent will be based on the security relationship between the three North American Free Trade Agreement countries, as determined through ongoing talks to renegotiate NAFTA.

Trump is justifying the tariffs under section 232 of a 1962 U.S. law that gives the president authority to impose tariffs in the name of national security.

The official also said that if the U.S. reaches an agreement with Canada and Mexico, the tariffs on other countries may need to be "modestly" increased in order to defend American industries.

Earlier today, Prime Minister Justin Trudeau told CBC News that he had a "level of confidence" about the issue because of the Liberal government's outreach efforts. The prime minister has been making calls to global allies and American politicians to rally support for an exemption for Canada.