Federal health officials say the tainted lettuce that led to a nationwide food safety alert to not consume any romaine lettuce likely originated from California. Scott Gottlieb, the commissioner of the Food and Drug Administration, said the goal is to withdraw the product that's at risk of being contaminated and then restocking the market.

In a Twitter thread on Thanksgiving Day, Gottlieb explained that a large part of why such a broad warning was issued was because some lettuce packing doesn't specify where the product was grown. Most of the romaine lettuce that's currently in the market is from California, according to Gottlieb. New romaine lettuce will be harvested soon from Yuma, Florida and other regions, Gottlieb said.

Gottlieb also said the FDA will begin a special effort to sample and test romaine lettuce for contamination throughout the market and investigate why officials see some continued risks with romaine. On Friday, Gottlieb said via Twitter that officials are working with growers and distributors on labeling produce for location and harvest date.