American companies should be ready to stop treating China as an economic competitor and start viewing it as a national security threat, former ambassador to the United Nations and Republican presidential candidate Nikki Haley said Monday.

“I think China’s an enemy. I think we have to take them incredibly seriously. And the problem is, you can look at dollars and cents or you can look at a threat to America,” Haley said on CNBC’s “Squawk Box.”

“Companies and people have said for too long, ‘We’ll deal with China tomorrow.’ But China is dealing with us today. We’ve got to address this,” she added.

Haley said “every company needs to have a Plan B” in the event that China decides to “pull the rug out from under us.” She called Beijing “the biggest threat we’ve had since Pearl Harbor.”

The former governor of South Carolina also criticized Treasury Secretary Janet Yellen, who recently said the U.S. relationship with China need not be a “winner take all” contest.

“To even say that means you don’t understand China,” Haley said of Yellen.

Haley’s latest remarks build on the hawkish position she laid out last month in a Wall Street Journal op-ed, in which she vowed to push U.S. businesses “to leave China as completely as possible.”

She also urged businesses to forge stronger ties with U.S. allies, such as India, Japan and South Korea, to become less dependent on China.

Haley pointed to a series of actions taken by China’s communist leadership in recent years that she said pose a multi-layered economic and security threat to the United States. They include buying hundreds of thousands of acres of U.S. farmland, purchasing the country’s largest pork producer, floating spy balloons over America, spreading propaganda in universities, lobbying Congress through “front companies,” rapidly building up a massive naval fleet, stealing U.S. intellectual property and developing new weapons.

The Chinese embassy in Washington, D.C., did not immediately comment on Haley’s remarks. Chinese government officials frequently insist that Beijing merely seeks a mutually beneficial, “win-win” relationship with the United States. But American diplomats privately joke that “win-win” here means China wins twice.

Haley also suggested that China’s role in the U.S. fentanyl crisis raises questions about the future of the bilateral trade relationship.

Many of the precursor chemicals that make up fentanyl originate in China before being illegally diverted to Mexico, where they are processed by cartels to create the deadly synthetic opioid. The Department of Justice has said fentanyl overdoses are the leading cause of death for Americans ages 18 to 49.

“I think if it means us ending normal trade relations, you go to China and say, ‘We’ll end normal trade relations until you stop killing Americans,'” she said.

Haley’s alarm-ringing on China comes as she seeks to distinguish herself in the Republican presidential primary, which has so far been dominated by former President Donald Trump.

Only one of Trump’s competitors, Florida Gov. Ron DeSantis, has consistently garnered double-digit support in national polls of the primary race. The rest of the field, including Haley, has struggled to gain traction with voters.

Haley took aim at DeSantis over his ongoing feud with Disney, which stemmed from the entertainment giant’s opposition to a controversial classroom bill in Florida. While she disagrees with Disney’s stance, “I also don’t think that governors should spend taxpayers dollars suing companies.”

Still, it is difficult to predict how forcefully criticizing China will help to set Haley, or any candidate, apart from the pack in the 2024 election cycle.

This is in large part because polls consistently show that a hawkish attitude towards Beijing is one of the few policy positions that enjoys broad support among both Democrats and Republicans.

As President Joe Biden mounts a reelection campaign, his administration is taking a hard line against China that bears a strong similarity to those of Republicans like Haley.

FBI Director Christopher Wray testified this month that no other country presents a “more comprehensive threat to our ideas, our innovation [and] our economic security.”

Asked about the state of the Republican primary, Haley described it as a marathon, “not a sprint.”

She also said that she would support Trump if he is the eventual Republican nominee. “I’m not going to have a President Kamala Harris,” she said, a reference to the view held by many Republican voters that Biden, who turned 80 last year, is too old to be president.