Two days before U.S. President Donald Trump's deadline to finalize trade negotiations, Canada hasn't closed a deal with the United States, Prime Minister Mark Carney said.

"It is possible that [negotiations] may not conclude by the first of August," Carney said at a news conference on Wednesday. "But we'll see with the teams there. We're working hard."

Trump set an Aug. 1 deadline for Canada to reach a trade deal and has threatened to impose a 35 per cent tariff on goods that don't comply with the Canada-U.S.-Mexico Agreement (CUSMA).

That rate would apply to Canadian exports currently being tariffed at 25 per cent, under Trump's emergency powers, citing what he says is a national security threat from fentanyl trafficking.

"The president has been very clear … that there are certain sectors that are strategic, in their judgment, to the United States' economy: aluminum steel, automobiles, pharmaceuticals, semiconductors and lumber," Carney said. 

The prime minister previously hinted that the Canadian government is in no rush to finalize a deal by Friday, saying last week that his objective is "not to reach a deal whatever it costs." 

Monday, Carney said in P.E.I. that trade negotiations with the United States are at an "intense phase." 

On Wednesday, Trump announced that the U.S. would levy a 50 per cent tariff on copper products such as pipes and wiring, starting Friday. 

The White House said it would apply only to semi-finished copper products and other products that heavily use copper when being manufactured.

Trump suggested last Friday that the U.S. might not reach an agreement with Canada and that more tariffs could be in store for the country.

"I think Canada could be one where there's just a tariff, not really a negotiation," Trump told reporters. 

Canada's top trade negotiators — Kirsten Hillman, Canada's ambassador to the U.S., and Dominic LeBlanc, minister responsible for Canada-U.S trade — have also downplayed the likelihood of the two countries reaching a deal by Aug. 1.

"It's important for us to recognize that there is a time when the deal is the right deal, and it's important for us to be in a position to continue negotiating until we get to that point," Hillman said last week.