The White House is preparing contingency plans to keep supply chains moving in the event rail workers go on strike at the end of the week.

Press secretary Karine Jean-Pierre told reporters that the administration is working with shippers, truckers and air freight workers “to see how they can step in and keep goods moving in case of this rail shutdown. 

“The administration has also been working with relevant agencies to assess what supply chains and commodities are most likely to face severe disruptions and available authorities to keep goods moving,” Jean-Pierre added.

The companies that operate railways for freight trains and the unions who work those rails have until Friday to agree to a new contract. Without a deal, workers could go on strike, crippling supply chains that depend on freight trains.

A strike could also impact passenger rail service. Amtrak does not own the railways where its trains operate in certain parts of the country but instead operates on those owned by freight companies. On Monday, the company canceled some long-distance routes in anticipation of a potential strike.

Five of the 12 unions representing rail workers have reached tentative agreements with railroads to enact the Presidential Emergency Board recommendations, which call for 24 percent pay raises, back pay and cash bonuses.

But the bulk of rail workers belong to unions that haven’t yet struck a deal with companies.

Should the workers vote to strike, Congress could intervene to halt it.

Jean-Pierre on Tuesday also confirmed that Biden personally called union leaders and company officials on Monday to urge them to find a solution and avoid a strike.

“We have made crystal clear to the interested parties the harm that American families, businesses and farmers and communities would experience if they were not to reach a resolution,” Jean-Pierre said.