Long lines of container ships queued up outside major U.S. ports on Thursday as the biggest dockworker strike in nearly half a century entered its third day preventing unloading and threatening shortages of everything from bananas to auto parts.

The strike by the International Longshoremen's Association (ILA) union has blocked goods from food to automobile shipments across dozens of ports from Maine to Texas, a disruption that analysts warn will cost the economy billions of dollars a day.

President Joe Biden on Tuesday signaled his support for the tens of thousands of dockworkers on strike at U.S. ports and issued a warning to shipping companies.