The Food and Drug Administration said it had an alert in place since October 10 for specific imports containing milk but that new data indicated that "a countrywide import alert is warranted."
The FDA said it would test "a range of protein-containing products beyond just dairy and dairy-containing products" for contamination and would "take appropriate regulatory action" if needed.
The import alert covers a range of products including beverages, candy, baby food and pet foods. It allows inspectors to seize any products suspected of being contaminated.
At the same time, the FDA warned against consuming an infant formula manufactured in China as well as more than a dozen products including biscuit, instant coffee and tea products.
At least four children have died of kidney failure and 53,000 have fallen ill in China this year after drinking milk or consuming dairy products laced with melamine, which is usually used in making plastics and fertilizers.
The dairy scandal has expanded worldwide with several governments recalling or banning Chinese products with milk content.
In a related matter, the US government said FDA Commissioner Andrew von Eschenbach and Health and Human Services Secretary Mike Leavitt will travel to China next week "for consultations with their Chinese counterparts" on safety issues and to open three new FDA offices in China.
The visit is "part of an ongoing strategy to address the food safety issues in both countries and to share ideas to address global food safety," a statement from Leavitt's office said.
"This will include a discussion of the recent outbreak of food borne illness in the United States related to fresh produce as well as the melamine contamination of dairy products in China," the statement said.