WASHINGTON ― President-elect Donald Trump has asked his chief of staff to get him a list of every American company that has plans to shift production to another country.

“Hey, Reince, I want to get a list of companies that have announced they’re leaving,” Trump said to Reince Priebus last week in the middle of an on-the-record interview with Time magazine that was published on Wednesday.

“I can call them myself,” Trump said. “Five minutes apiece. They won’t be leaving. O.K.?”

Trump had just struck a deal with Carrier Corporation to stop the company from closing its factory in Indiana, saving 800 American jobs. As part of the process, Trump had called up the CEO of United Technologies, Carrier’s parent company, and asked him to reconsider.

If Trump is going to spend five minutes on the phone with every CEO of every company that’s planning to shift production abroad, he’s going to be on the phone for many hours, because Carrier’s case is not at all unusual.

Rexnord Corporation is a symbol of the challenge confronting Trump. The company, which owns a plant about a mile from Carrier’s furnace factory, is planning to lay off 300 workers and close the factory next year.

Trump has already put Rexnord on notice, firing a warning shot via Twitter on Friday.

“Rexnord of Indiana is moving to Mexico and rather viciously firing all of its 300 workers,” Trump tweeted. “This is happening all over our country. No more!”

The company has not responded to repeated requests for comment.

Draper Alumbaugh, who has worked at Rexnord for 13 years, said the company’s Mexico plan is pure corporate greed, since the company is profitable. He voted for the president-elect because of Trump’s promise to stop companies from offshoring jobs, and he’s grateful for Trump’s efforts so far ― but even after the Carrier deal he’s skeptical that Rexnord can be stopped.

“I don’t think he’ll save the jobs. I just don’t think there’s enough of us,” Alumbaugh, 37, said in an interview.

Another problem Alumbaugh sees is that Rexnord doesn’t do nearly as much federal contracting as United Technologies does, meaning Trump will have less leverage in the form of threatening to withhold revenue.

“I think that he might make an attempt, because how bad would it look if he didn’t? I mean we’re in the same union, a half a block away from Carrier,” Alumbaugh said.

The United Steelworkers Local 1999 represents workers at both companies. Chuck Jones, president of the Local 1999, said he believes Trump’s public statements about stopping Rexnord and companies like it from offshoring jobs amount to a clear promise to Rexnord workers.

“President-elect Trump said numerous times that none of these companies are gonna leave this country, so we’re gonna hold him to his word on that,” Jones said in an interview. “We haven’t gave up the fight by no means on Rexnord or the remaining jobs at Carrier.”

United Technologies is still planning to lay off more than 1,000 workers next year, despite the agreement with Trump, which included tax breaks from the state of Indiana.

It’s a scenario playing out across the country. This year, the U.S. Labor Department has certified petitions for Trade Adjustment Assistance for workers at more than 1,000 firms cutting jobs due to foreign trade. Some of the petitions are for workers whose jobs or hours have been cut because of cheaper imports, but most are for workers at firms shifting production abroad. The trade assistance certifications give laid off workers access to unemployment insurance and retraining programs.

Instead of spending hours and hours on the phone, a shortcut for Trump would be to impose tariffs on imports from companies that offshore jobs, something he has said he would do. But economists say such a strategy would cause other countries to impose tariffs on U.S. exports, starting a trade war that would cost millions of jobs. Economists also generally blame automation for manufacturing job losses more than they blame foreign trade.

Sen. Joe Donnelly (D-Ind.), who has pleaded with Trump not to ignore workers losing their jobs at other Indiana plants, told The Huffington Post he’s still hopeful about Rexnord. Last month, he said, he had a meeting with the company but didn’t make much headway.

“I appreciate President-elect Trump’s working together with us on this and we’re hoping to get it done,” Donnelly said.