As negotiations between labor unions and freight railroad companies over a new contract continue, Amtrak prepared for a potential strike by cancelling several of its long-distance routes. If a deal is not reached, a strike could begin as soon as Friday. The affected routes, which closed starting Tuesday, includes:

• The Southwest Chief route from Chicago to Los Angeles.
• The Empire Builder route from Chicago to Seattle.
• The California Zephyr route from Chicago to San Francisco.
• The Los Angeles to San Antonio portion of the Texas Eagle route.

“While we are hopeful that parties will reach a resolution, Amtrak has now begun phased adjustments to our service in preparation for a possible freight rail service interruption later this week,” Amtrak said in a statement Monday.

While negotiations do not involve Amtrak or its workers, the company said a freight railroad strike could significantly affect Amtrak’s passenger rail service routes. On Monday, the Biden administration warned a strike would pose “an unacceptable outcome” to the U.S. economy that could cost $2 billion a day.

“The parties continue to negotiate, and last night [Labor] Secretary [Marty Walsh] again engaged to push the parties to reach a resolution that averts any shutdown of our rail system,” a Labor Department spokesperson said Monday. “All parties need to stay at the table, bargain in good faith to resolve outstanding issues, and come to an agreement.”

Reuters contributed to this report.