Chrystia Freeland, former Canadian deputy prime minister, said on Sunday that President Trump’s decision to impose 25 percent tariffs on Canadian goods is a “betrayal” and an “act of economic warfare.”

Trump, on Saturday, signed tariffs on Mexico, Canada and China, which are set to go into effect on Tuesday. Canadian energy imports will only be tariffed at 10 percent. Trump, in signing the tariffs, cited concerns over illegal immigration and fentanyl smuggling.

In an interview on CNN’s “Fareed Zakaria GPS,” Freeland pushed back on those concerns, saying Trump’s “pretexts are utterly ludicrous” and noting the relatively low incidence rate for fentanyl at the northern border.

“This action is utter madness,” she continued. “It is a betrayal of America’s closest friend, of your ally, your neighbor, your best partner in the whole world. It is an act of economic warfare, and the president was clear just this morning, it is a direct attack on our sovereignty.”

“Americans are going to be astonished by the Canadian response,” she added. “We’re hurt, for sure, because we’re your friends and neighbors, but most of all, we’re angry, and we are united and resolute, and Canada is the true north, strong and free. We love our country, and we are united. We are strong, we’re smart. We’re going to fight for our country. We’re going to fight for Canada, and we’re going to be successful.”

Freeland is on track to succeed Canadian Prime Minister Justin Trudeau as party leader, after Trudeau announced his resignation last month. Freeland previously served as deputy prime minister and finance minister under Trudeau, but she resigned in December.

Freeland touted Canada as the U.S.’s “largest market for the United States” and questioned the logic behind the tariffs, which she described as akin to “punching us in the face.”

“We know Americans. We know that for you guys, the customer is always right. We’re your biggest customer. It doesn’t make a lot of sense to be punching us in the face,” Freeland said.

She also said the tariffs were illogical because they are “self-harming” to Americans.

“By putting tariffs on the stuff that Canada sells you, you are going to hurt Americans. You have put a tariff. You’re putting a tariff on the oil and gas that we sell you that is going to make prices at the pump, prices at grocery stores a lot higher,” she said.

Freeland noted that Canadians are united on this issue, which the former deputy prime minister said matters a lot more to Canadians than it does to Americans.

“This matters to us so much more than it matters to you. Our very sovereignty is at stake. You are seeing a phenomenal, united and resolute response across Canada,” she said.

“And for Americans, does this really matter to you at all? I mean, do Americans wake up in the morning and say, ‘Wow, we got to beat up on those Canadians?’ I don’t think so,” she said. “I think Americans actually recognize that we are a great partner, a great neighbor, a great friend. That this is ridiculous. It is not worth Americans suffering over this. As the Prime Minister said, we do not want this conflict, but we’re not going to give in.”