Canadian Foreign Minister Melanie Joly said on Monday she would soon be talking to counterparts in allied nations in a bid to fend off tariffs that U.S. President Donald Trump is threatening to impose.

Tim McMillan, a former head of the Canadian Association of Petroleum Producers, warned that Ottawa should avoid the temptation to retaliate by cutting off oil supplies from Alberta, which make up half of U.S. oil imports, saying it “would be a huge mistake.”