U.S. officials on Thursday made recommendations to a Chinese delegation, encouraging them to tighten food export regulations.

The proposal included building a registry of Chinese firms authorized to export products to the U.S. and allowing U.S. inspectors into China.

U.S. officials also said Chinese companies must work to establish consumer confidence while authorities must ensure the safety of the products being exported.

Meanwhile, U.S. health officials have begun checking shipments of toothpaste from China after thousands of tubes of imported toothpaste were withdrawn from the marketplace in other countries.

Health authorities in the Dominican Republic on Tuesday issued a recall of the Chinese-made Excel and Mr. Cool toothpastes after tests showed the products contained diethylene glycol, a chemical used in antifreeze and brake fluid. The toothpaste was also sold in Panama and Australia.

Doug Arbesfeld, a U.S. Food and Drug Administration spokesman, said Wednesday that there was no indication that the recalled brands of toothpaste had been sold in the U.S. The checks were being conducted as a precautionary measure, he said.

Chinese officials said Wednesday that they are launching a consumer product safety investigation into the tainted toothpaste.

The toothpaste recall follows an extensive recall of more than 100 brands of pet food in North America. Chinese wheat flour used in the food was tainted with melamine, a chemical used to make plastics and fertilizers, the U.S. Food and Drug Administration later said.

In April, the Canadian Food Inspection Agency issued border lookouts for wheat gluten, soy proteins, corn glutens and rice proteins from China.

With files from the Associated Press