CHICAGO (Reuters) - Canada has suspended imports from the biggest U.S. pork processing plant, a facility run by Smithfield Foods ( SFD ) in Tar Heel, North Carolina, the company said on Friday.

The suspension comes as the U.S. and Canada have engaged in a heated dispute over trade tariffs.

Smithfield is working with the USDA to resolve the matter, spokesman Jim Monroe said.

"The issue pertains to a limited number of certain offal shipments," he said, and did not elaborate on the issue.

Canada blocked meat products from Smithfield's facility starting on Thursday, according to a USDA website.

President Donald Trump on Thursday exempted goods from Canada and Mexico under a North American trade pact for a month from the 25% tariffs that he had imposed earlier this week.