Vowing to stop machines from taking their jobs, 45,000 U.S. longshoremen are threatening to go on a strike that would shut ports on the East and Gulf coasts and could damage the American economy just as President-elect Donald Trump returns to the White House.

President-elect Donald Trump is offering his support for the dockworkers union before their contract expires next month at Eastern and Gulf Coast ports.

The union representing striking U.S. dockworkers has reached a deal to suspend the strike until Jan. 15 to provide time to negotiate a new contract.

U.S. ports from Maine to Texas are closed due to a strike by the union representing about 45,000 dockworkers.

Determined to thwart the automating of their jobs, about 45,000 dockworkers along the U.S. East and Gulf Coasts are threatening to strike on Oct. 1, a move that would shut down ports that handle about half the nation’s cargo from ships.